Diadexus (VXGN) 10-K 11 Mar 14 2013 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2013	Mar. 06, 2014	Jun. 30, 2013
Document And Entity Information [Abstract]	'	'	'
Document Type	'10-K	'	'
Amendment Flag	'false	'	'
Document Period End Date	31-Dec-13	'	'
Document Fiscal Year Focus	'2013	'	'
Document Fiscal Period Focus	'FY	'	'
Trading Symbol	'DDXS	'	'
Entity Registrant Name	'diaDexus, Inc.	'	'
Entity Central Index Key	'0001036968	'	'
Current Fiscal Year End Date	'--12-31	'	'
Entity Well-known Seasoned Issuer	'No	'	'
Entity Current Reporting Status	'Yes	'	'
Entity Voluntary Filers	'No	'	'
Entity Filer Category	'Smaller Reporting Company	'	'
Entity Common Stock, Shares Outstanding	'	54,813,385	'
Entity Public Float	'	'	$35.30

Balance_Sheets

Balance Sheets (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$16,847	$12,851
Short-term investment securities	'	747
Accounts receivable, net of reserve of $5 and $0 at December 31, 2013 and 2012, respectively	3,027	2,789
Inventories	460	134
Assets held for sale	'	300
Prepaid expenses and other current assets	845	871
Total current assets	21,179	17,692
Restricted cash	1,400	1,400
Property and equipment, net	968	1,250
Other long-term assets	100	142
Total assets	23,647	20,484
Current liabilities:	'	'
Accounts payable	611	469
Notes payable, current portion	2,763	272
Deferred revenues, current portion	228	317
Deferred rent, current portion	51	'
Unfavorable lease obligations	697	588
Accrued and other current liabilities	2,203	1,953
Total current liabilities	6,553	3,599
Non-current portion of notes payable	7,047	4,621
Non-current portion of deferred revenue	'	225
Non-current portion of deferred rent	336	363
Non-current portion of unfavorable lease obligation	1,777	2,475
Other long term liabilities	414	346
Total liabilities	16,127	11,629
Commitments and contingencies (Note 14)	'	'
Stockholders' equity:	'	'
Preferred Stock, $0.01 par value, 19,979,500 shares authorized; none issued or outstanding	'	'
Common stock, $0.01 par value; 100,000,000 shares authorized; 54,751,685 and 53,890,314 shares issued and outstanding at December 31, 2013 and December 31, 2012, respectively	548	539
Additional paid-in capital	206,868	206,048
Accumulated deficit	-199,896	-197,732
Total stockholders' equity	7,520	8,855
Total liabilities and stockholders' equity	$23,647	$20,484

Balance_Sheets_Parenthetical

Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, except Share data, unless otherwise specified
Statement Of Financial Position [Abstract]	'	'
Accounts receivable, reserve	$5	$0
Preferred stock, par value	$0.01	$0.01
Preferred stock, shares authorized	19,979,500	19,979,500
Preferred stock, shares issued	'	'
Preferred stock, shares outstanding	'	'
Common stock, par value	$0.01	$0.01
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	54,751,685	53,890,314
Common stock, shares outstanding	54,751,685	53,890,314

Statements_of_Comprehensive_Lo

Statements of Comprehensive Loss (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Revenues:	'	'
Product sales	$24,561	$18,066
Royalty revenue	18	2,405
License revenue	305	305
Total revenues	24,884	20,776
Operating costs and expenses:	'	'
Product costs	7,222	6,296
Sales and marketing	7,482	5,465
Research and development	4,709	4,196
General and administrative	7,486	7,217
Total operating costs and expenses	26,899	23,174
Loss from operations	-2,015	-2,398
Interest income, interest expense and other income (expense), net:	'	'
Interest income	4	16
Interest expense	-488	-395
Other income (expense), net	340	-10
Loss before income tax	-2,159	-2,787
Income tax provision	-5	-2
Net loss	-2,164	-2,789
Basic and diluted net loss per share:	($0.04)	($0.05)
Weighted average shares used in computing basic and diluted net loss per share	54,329,424	53,198,336
Comprehensive loss:	'	'
Net loss	-2,164	-2,789
Net change in unrealized gain/(loss) on available for sale securities	'	5
Comprehensive loss	($2,164)	($2,784)

Statements_of_Cash_Flows

Statements of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Operating activities:	'	'
Net loss	($2,164)	($2,789)
Adjustments to reconcile net loss to net cash used in operating activities:	'	'
Gain on disposal of assets	-340	4
Depreciation and amortization	531	503
Stock-based compensation	632	362
Provision for doubtful accounts and rebate reserve (reversal)	5	-24
Amortization on investments	'	26
Noncash interest expense	31	29
Noncash interest associated with notes payable	140	125
Unfavorable lease	-589	-492
Inventory written off	'	31
Changes in operating assets and liabilities:	'	'
Accounts receivable	-243	-357
Inventory	-326	-48
Prepaid expenses, other current assets and other long-term assets	3	138
Accounts payable	174	-386
Accrued liabilities and other long-term liabilities	342	-343
Deferred rent	24	97
Deferred revenue	-314	-319
Net cash used in operating activities	-2,094	-3,443
Investing activities:	'	'
Purchases of property and equipment	-302	-605
Maturities of available-for-sale investments	747	7,219
Purchases of available-for-sale investments	'	-1,245
Proceeds from sale of assets, net	634	2
Release of restricted cash	'	400
Net cash provided by investing activities	1,079	5,771
Financing activities:	'	'
Proceeds from notes payable	5,000	'
Debt issuance costs	-50	-50
Proceeds from stock option exercises	61	89
Net cash provided by financing activities	5,011	39
Net increase in cash and cash equivalents	3,996	2,367
Cash and cash equivalents, beginning of year	12,851	10,484
Cash and cash equivalents, end of year	16,847	12,851
Supplemental disclosure:	'	'
Cash paid for interest	315	267
Non-cash investing and financing transactions	'	'
Issuance of warrants for common stock in connection with debt	136	48
Net change in accounts payable from acquisition of property and equipment	-32	51
Net change in accrued liabilities from acquisition of property and equipment	($16)	$27

Statements_of_Stockholders_Equ

Statements of Stockholders' Equity (USD $)	Total	Common Stock [Member]	Additional Paid in Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Deficit [Member]
In Thousands, except Share data
Beginning Balance at Dec. 31, 2011	$11,140	$531	$205,557	($5)	($194,943)
Beginning Balance, Shares at Dec. 31, 2011	'	53,067,045	'	'	'
Stock-based compensation - employee under ASC 718	362	'	362	'	'
Issuance and sale of common stock under stock-based compensation plans	89	8	81	'	'
Issuance and sale of common stock under stock-based compensation plans, Shares	'	823,269	'	'	'
Issuance of warrants	48	'	48	'	'
Change in unrealized gain (loss) on available-for-sale securities	5	'	'	5	'
Net loss	-2,789	'	'	'	-2,789
Ending Balance at Dec. 31, 2012	8,855	539	206,048	'	-197,732
Ending Balance, Shares at Dec. 31, 2012	'	53,890,314	'	'	'
Stock-based compensation - employee under ASC 718	632	'	632	'	'
Issuance and sale of common stock under stock-based compensation plans	61	5	56	'	'
Issuance and sale of common stock under stock-based compensation plans, Shares	'	474,587	'	'	'
Issuance of warrants	136	'	136	'	'
Issuance and sale of common stock under warrants	'	4	-4	'	'
Issuance and sale of common stock under warrants, Shares	'	386,784	'	'	'
Net loss	-2,164	'	'	'	-2,164
Ending Balance at Dec. 31, 2013	$7,520	$548	$206,868	'	($199,896)
Ending Balance, Shares at Dec. 31, 2013	'	54,751,685	'	'	'

Business_Overview

Business Overview	12 Months Ended
	Dec. 31, 2013
Accounting Policies [Abstract]	'
Business Overview	'
	1. Business Overview
	Formation of the Company
	We are a life sciences company focused on developing and commercializing proprietary cardiovascular diagnostic products addressing unmet needs in cardiovascular disease (“CVD”). We sell our diagnostic products to laboratories. Physicians order testing for their patients from these laboratories and use the results to aid in assessing their patients risk for CVD.
	The Company’s products, PLAC® Tests, are designed to provide information, over and above traditional risk factors, to help identify individuals at increased risk of suffering a heart attack or stroke. Some of these events may be reduced with earlier detection and more aggressive risk-reducing strategies, including treatment to lower LDL-cholesterol goals with statins. The Company has commercialized two PLAC Tests. One test measures the mass of circulating Lp-PLA2 in the blood, the PLAC ELISA Test . The PLAC ELISA Test is the only Lp-PLA2 blood test cleared by the US Food and Drug Administration (the “FDA”) to aid in assessing risk for both coronary heart disease and ischemic stroke associated with atherosclerosis. The second test, the PLAC Test for Lp-PLA2 Activity, is an enzyme assay for the quantitative determination of Lp-PLA2 activity levels in human plasma and serum on automated clinical chemistry analyzers, to be used in conjunction with clinical evaluation and patient risk assessment as an indicator of atherosclerotic cardiovascular disease. The Company is currently commercializing the PLAC ELISA Test in the United States and Europe and the PLAC Activity Test in Europe.
	The Company has incurred substantial losses since the inception, and expects to continue to incur net losses for at least the next few years. To date, the Company has funded its operations primarily through private placements of preferred stock and debt financing, as well as through revenue generated from the sale of products.
	In September 2011, the Company entered into a Loan and Security Agreement with Comerica Bank, which was amended in September 2012 and again in October 2013 (see Note 9 of the Notes to Financial Statements included in this Annual Report on Form 10-K). The Loan and Security Agreement contains various covenants. If the Company breaches any of these covenants or is unable to make a required payment of principal or interest, or experiences a material adverse change to its business, it could result in a default under the loan. Additionally, the Company is required to (i) maintain a liquidity ratio of not less than 1.25 to 1 and (ii) ensure its cumulative net loss does not exceed $6,000,000 beginning July 1, 2013 in accordance with GAAP, and failure to do so could result in a default under the loan. Upon the occurrence of an event of default under the loan, the bank could elect to declare all amounts outstanding to be immediately due and payable. If the Company is unable to repay those amounts, the bank could proceed against the collateral granted to them to secure such indebtedness. The Company has pledged substantially all of its assets, other than its intellectual property, as collateral under the loan.
	Our future liquidity requirements may increase beyond currently expected levels if we fail to maintain compliance with the loan covenants. In order to meet the future liquidity needs, we may become reliant on additional equity and/or debt financing. Additional funding may not be available when needed or on terms acceptable us. Any additional equity financing may be dilutive to stockholders, and debt financing, if available, may involve restrictive covenants. We cannot assure you that it will be able to raise any such additional funding or, if available, that such funding would be on favorable terms.
	PLAC Test ELISA Kit
	The Company introduced its initial PLAC Test ELISA Kit (the “PLAC ELISA Test”) in 2004 uses microplate technologies to measure levels of Lp-PLA2. The infrastructure for performing microplate tests typically exists only at large and midsize clinical reference laboratories and large hospitals, which must be certified by the US Department of Health and Human Services (“DHHS”) for high-complexity diagnostics under the Clinical Laboratory Improvement Amendments (“CLIA”). Smaller hospitals and clinics can order the PLAC ELISA Test for their patients from those institutions that are able to perform microplate tests and offer the PLAC ELISA Test. Patients can have their blood drawn at a local laboratory and shipped to the more advanced institutions for analysis. The Company markets the PLAC ELISA Test in the United States, Europe, Israel and Mexico.
	PLAC Test for Lp-PLA2 Activity
	The Company introduced the PLAC Test for Lp-PLA2 Activity (the “PLAC Activity Test”) in Europe in March 2012. This PLAC Activity Test is an enzyme assay for the quantitative determination of Lp-PLA2 activity levels in human serum or plasma. The PLAC Activity Test allows for the measurement of Lp-PLA2 using automated clinical chemistry analyzer technology. This clinical chemistry technology is more prevalent than the microplate technology used for the PLAC ELISA Test, such that a broader array of institutions can conduct the test. This group includes clinical laboratories and hospitals of all sizes and physician operated laboratories (“POLs”). In addition, the sample handling requirements are much less stringent for the PLAC Activity Test compared to the PLAC ELISA Test, allowing greater ease of use for those facilities processing specimens. The PLAC Activity Test is currently available in Europe for use in conjunction with clinical evaluation and patient risk assessment as an indicator of atherosclerotic cardiovascular disease. The Company affixed the CE marking for this intended use by self-certification in January 2012. The PLAC Activity Test is available on a commercial basis only in Europe. The Company plans to pursue 510(k) clearance for this test from the FDA and eventually commercialize this assay format in the United States if the Company obtains FDA clearance.
	In September 2013, the Company had a pre-submission meeting with the FDA, as a result of which the Company is advancing its clinical program to support the submission of the PLAC Activity Test to the FDA. The Company has partnered with a large longitudinal cardiovascular disease study to validate the PLAC Activity Test. The Company anticipates that the clinical study sample analysis will be initiated prior to the end of the first quarter of 2014.
	All references in these notes to financial statements to the “Company,” “we,” “us” and “our” refer to diaDexus, Inc. (f/k/a VaxGen, Inc.), a Delaware corporation, unless the context requires otherwise.

Summary_of_Significant_Account

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2013
Accounting Policies [Abstract]	'
Summary of Significant Accounting Policies	'
	2. Summary of Significant Accounting Policies
	Basis of Presentation
	The accompanying financial statements have been prepared in accordance with US generally accepted accounting principles (“GAAP”). Certain amounts previously reported in the financial statements have been reclassified to conform to the current year presentation. Such reclassifications did not affect net loss, stockholders’ equity or cash flow.
	Starting in January 2013, the Company includes excise tax collected from customer product sales. The Company recognized $402,000 and $455,000 in charged excise tax within product revenue and product costs, respectively, for the year ended December 31, 2013. For the year ended December 31, 2012, there was no excise tax recognized within product revenue and product costs.
	Use of Estimates
	The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets, including assets held for sale, and liabilities at the date of the financial statements and the reported amount of revenues and expenses during the reporting period. Actual results may differ significantly from those estimates.
	The Company considers the accounting policies related to revenue recognition, stock-based compensation, and income taxes to be the most critical accounting policies, because they require the Company to make estimates, assumptions and judgments about matters that are inherently uncertain.
	Cash and Cash Equivalents
	The Company considers all highly liquid investments purchased with original maturities of 90 days or less to be cash equivalents. Cash equivalents consist primarily of money market accounts and treasury securities.
	Restricted Cash
	Restricted cash represents term deposits, which expire in December 2016, held at one financial institution as collateral for the lease of the Company’s facilities in South San Francisco.
	Available-for-Sale Investments
	The Company classifies its investments as available-for-sale. Available-for-sale investments are recorded at fair value based on quoted market prices, with the unrealized gains or losses included in accumulated other comprehensive income (loss) within stockholders’ equity, except that any unrealized losses which are deemed to be other than temporary are reflected in the statement of operations. Management assesses each of these investments on an individual basis to determine if the decline in fair value was other than temporary. The amortized cost of debt securities is adjusted for amortization of premiums and accretion of discounts to maturity. Such amortization or accretion is included in interest income. Realized gains or losses on sales of available-for-sale securities are reported in other income or expenses as incurred. The cost of securities sold is based on the specific identification method. Interest and dividends on available-for-sale securities are recorded in interest and other income.
	Inventory
	Inventories are stated as the lower of cost or market. Cost is determined using the first in, first out method. Market value is determined as the lower of replacement cost or net realizable value.
	Property and Equipment
	Property and equipment are recorded at cost and depreciated over their estimated useful lives using the straight-line method. Laboratory equipment, computers, software, and office furniture are depreciated over three years. Leasehold improvements are recorded at cost and amortized over the term of the lease or their useful life, whichever is shorter. Maintenance and repairs are expensed as incurred.
	Segments
	The Company has one reportable segment and uses one measurement of profitability to manage its business. All long-lived assets are maintained in the United States of America.
	Revenues by geography are based on the billing address of the customer. The following table sets forth revenues by geographic area (in thousands):
		Years Ended December 31,
		2013		2012
	United States	$	24,316	$	20,443
	Europe		330		245
	Rest of the world		238		88
		$	24,884	$	20,776
	Revenue Recognition
	Revenues are generated from product sales, royalties earned, license fees and contract arrangements, and recorded net of customer and distributor discounts. Revenue is recognized when the four basic criteria of revenue recognition are met: (i) a contractual agreement exists; (ii) delivery of product has occurred and risk of loss and title has transferred, transfer of technology (intellectual property) has been completed or services have been rendered; (iii) the fee is fixed or determinable; and (iv) collectability is reasonably assured.
	License fee revenue including nonrefundable upfront fees, is deferred and recognized over the term of the underlying agreements. Royalty revenue is recognized when reportable product sales are confirmed. Revenue from technology licenses or other payments under collaborative agreements where the Company has a continuing obligation to perform is recognized as revenue over the expected period of the continuing performance obligation. The term of these underlying agreements ranges from two to ten years.
	Accruals
	In connection with the process of preparing financial statements, the Company estimates accrued expenses. This process involves communicating with our applicable personnel to identify services that have been performed on the Company’s behalf and estimating the level of service performed and the associated cost incurred for the service when the Company has not yet been invoiced or otherwise notified of actual cost. The majority of our service providers invoice us monthly in arrears for services performed. The Company makes estimates of accrued expenses as of each balance sheet date in the financial statements based on known facts and circumstances. The Company periodically confirms the accuracy of estimates with selected service providers and makes adjustments, if necessary.
	Research and Development
	Research and development expenses include internal and external costs. Internal costs include product development, regulatory support for technology, laboratory materials and supply costs and other technical support costs, including salaries and consultant fees. External expenses consist of sponsored research studies and investigator sponsored trials. Research and development costs are expensed as incurred.
	Impairment of Long-Lived Assets
	In accordance with Accounting Standards Codification (“ASC”) Subtopic ASC 360-10, impairment of long-lived assets is measured or assessed when events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable. Determination of recoverability is based on an estimate of undiscounted future cash flows resulting from the use of the asset and its eventual disposition. In the event that such cash flows are not expected to be sufficient to recover the carrying amount of the assets, the assets are written down to their estimated fair values. Long-lived assets to be disposed of are reported at the lower of carrying amount or fair value less costs to sell.
	Stock-Based Compensation
	The Company recognizes stock-based compensation expense for all stock-based payment awards in accordance with ASC 718, which requires the measurement and recognition of compensation expense for all stock-based payments made to employees and directors including employee stock option awards, based on estimated fair value. Stock-based compensation expense for expected-to-vest stock-based awards is valued under the single-option approach and amortized on a ratable basis, net of estimated forfeitures. The value of the portion of the award that is ultimately expected to vest is recognized as expense over the requisite service periods in the Company’s statements of operations for all periods presented.
	The assumptions used in computing the fair value of stock-based awards reflect the Company’s best estimates, but involve uncertainties relating to market and other conditions, many of which are outside of the Company’s control. In addition, the Company’s estimate of future stock-based compensation expense will be affected by a number of items including the Company’s stock price, the number of stock options the Company’s board of directors may grant in future periods, as well as a number of complex and subjective valuation adjustments and the related tax effect.
	The fair value of nonvested restricted stock units (“RSUs”) is based on the Company’s closing stock price on the date of grant.
	The net loss for the years ended December 31, 2013 and 2012 include employee stock-based compensation expense of $632,000 and $362,000, respectively. As of December 31, 2013, the total unrecorded stock-based compensation expense for unvested stock options, net of expected forfeitures, was $1.0 million, which is expected to be amortized over a weighted-average period of 2.24 years.
	Fair Value Measurements
	In accordance with ASC Subtopic 820-10 the carrying amounts of certain financial instruments of the Company, including cash equivalents, marketable securities and liabilities, continue to be valued at fair value. ASC Subtopic 820-10 defines fair value and provides guidance for using fair value to measure assets and liabilities and is applicable whenever assets or liabilities are required or permitted to be measured at fair value.
	The fair value estimates presented reflect the information available to the Company as of December 31, 2013. See Note 3, “Fair Value Measurements.”
	Deferred Rent
	Deferred rent consists of the difference between cash payments and the recognition of rent expense on a straight-line basis for the buildings the Company leases. The leases provide for fixed increases in minimum annual rental payments and the total amount of rental payments due over the lease terms are being charged to rent expense ratably over the life of the leases.
	Comprehensive Income (Loss)
	Comprehensive income (loss) represents all changes in stockholders’ equity except those resulting from investments or contributions by stockholders. The Company’s unrealized gains on available-for-sale securities represent the component of comprehensive income (loss) excluded from the Company’s net loss.
	Income Taxes
	The Company accounts for income taxes under the asset and liability method. Under this method, deferred tax assets and liabilities are determined based on the difference between financial statement and tax bases of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to affect taxable income. Valuation allowances are established when necessary to reduce deferred tax assets to the amounts expected to be realized.
	On January 1, 2009, the Company adopted ASC 740-10-25. For the years ended December 31, 2013 and 2012, the Company did not have any additional unrecognized tax benefits and there was no effect on its financial condition or results of operations as a result of adopting ASC 740-10-25. The Company’s practice is to recognize interest and/or penalties related to income tax matters in interest expense as incurred.
	Recent Accounting Pronouncements
	In July 2013, Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2013-11, “Presentation of an Unrecognized Tax Benefit when a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists (a consensus of the FASB Emerging Issues Task Force).” The amendments in this ASU provide guidance on the financial statements presentation of an unrecognized tax benefit when a net operating loss carryforward, a similar tax loss, or a tax credit carryforward exists. An unrecognized tax benefit should be presented in the financial statements as a reduction to a deferred tax asset for a net operating loss carryforward, a similar tax loss, or a tax credit carryforward with certain exceptions, in which case such an unrecognized tax benefit should be presented in the financial statements as a liability. The amendments in this ASU do not require new recurring disclosures and are effective for fiscal years, and interim periods within those years, beginning after December 15, 2013. We are currently assessing the impact of this ASU on our financial statements.

Cash_Cash_Equivalents_and_Inve

Cash, Cash Equivalents and Investments	12 Months Ended
	Dec. 31, 2013
Cash And Cash Equivalents [Abstract]	'
Cash, Cash Equivalents and Investments	'
	3. Cash, Cash Equivalents and Investments
	As part of its cash management program, the Company maintains a portfolio of marketable investment securities. The securities are investment grade and generally mature within one year and may include tax exempt securities and certificates of deposit. The fair value of substantially all securities is determined by quoted market prices. The Company maintains its cash in bank accounts, which at times may exceed federally insured limits. The Company has not experienced any losses on such accounts. The Company considers all highly liquid investments purchased with an original maturity of 90 days or less at the time of purchase to be cash equivalents.
	The following is a summary of cash, cash equivalents, and available-for-sale securities as of December 31, 2013 and 2012 (in thousands):
		December 31, 2013
		Cost Basis		Unrealized		Unrealized		Estimated
				Gains		Losses		Fair Value
	Cash and cash equivalents:
	Cash	$	12,800	$	—	$	—	$	12,800
	Money market funds		4,047		—		—		4,047
	Total cash and cash equivalents	$	16,847	$	—	$	—	$	16,847
		December 31, 2012
		Cost Basis		Unrealized		Unrealized		Estimated
				Gains		Losses		Fair Value
	Cash and cash equivalents:
	Cash	$	6,054	$	—	$	—	$	6,054
	Money market funds		6,797		—		—		6,797
	Total cash and cash equivalents	$	12,851	$	—	$	—	$	12,851
	Available-for-sale marketable securities:
	Certificate of deposits		747		—		—		747
	Total available-for-sale marketable securities	$	747	$	—	$	—	$	747
	Fair Value Measurements
	In accordance with ASC 820, the Company discloses and recognizes the fair value of its assets and liabilities using a hierarchy that prioritizes the inputs to valuation techniques used to measure fair value. The guidance establishes three levels of the fair value hierarchy as follows:
	Level 1: Observable inputs, such as quoted prices in active markets for identical assets or liabilities;
	Level 2: Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities, quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities;
	Level 3: Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.
	The following table represents the Company’s fair value hierarchy for its financial assets (cash equivalents and investments) measured at fair value on a recurring basis as of December 31, 2013 and 2012 (in thousands):
				Fair Value Measurements
		Balance as of		Quoted Prices		Significant		Significant
		December 31,		In Active		other		Unobservable
		2013		Markets for		Observable		Inputs
				Identical Assets		Inputs		Level 3
				Level  1		Level 2
	Assets:
	Cash	$	12,800	$	12,800	$	—	$	—
	Money market funds		4,047		4,047		—		—
	Restricted cash		1,400		—		1,400		—
		$	18,247	$	16,847	$	1,400	$	—
				Fair Value Measurements
		Balance as of		Quoted Prices		Significant		Significant
		December 31,		In Active		other		Unobservable
		2012		Markets for		Observable		Inputs
				Identical Assets		Inputs		Level 3
				Level  1		Level 2
	Assets:
	Cash	$	6,054	$	6,054	$	—	$	—
	Money market funds		6,797		6,797		—		—
	Certificates of deposit		747		—		747		—
	Restricted cash		1,400		—		1,400		—
		$	14,998	$	12,851	$	2,147	$	—
	The fair value of the notes payable is valued based on Level 2 inputs and approximates its book value. The fair value of the notes payable is based on the present value of expected future cash flows and assumptions about current interest rates and the credit worthiness of the Company. As of December 31, 2013, the notes payable is carried at face value of $10.0 million less any unamortized debt discount.
	The carrying value of other financial instruments, including cash, accounts receivable, accounts payable and other payables, approximates fair value due to their short maturities.

Inventory

Inventory	12 Months Ended
	Dec. 31, 2013
Inventory Disclosure [Abstract]	'
Inventory	'
	4. Inventory
	Inventory consists of the following (in thousands):
		December 31,		December 31,
		2013		2012
	Finished goods	$	361	$	61
	Raw materials		99		73
		$	460	$	134

Assets_Held_For_Sale

Assets Held For Sale	12 Months Ended
	Dec. 31, 2013
Text Block [Abstract]	'
Assets Held For Sale	'
	5. Assets Held For Sale
	Prior to the period reflected in this report, the Company had committed to a plan to sell the equipment related to its manufacturing facility and had determined that these assets met the criteria for, and had been classified as, “held for sale” in accordance with ASC Topic 360. The market approach was used in determining the fair market value of these assets.
	Total assets held for sale are as follows (in thousands):
				Fair Value Measurements Using
	Description	December 31,		Quoted		Significant		Significant		Year Ended
		2013		Prices in		Other		Unobservable		December 31,
				Active		Observable		Inputs		2013
				Markets for		Inputs		(Level 3)		Total
				Identical		(Level 2)				Gains (Losses)
				Assets
				(Level  1)
	Assets held for sale	$	—	$	—	$	—	$	—	$	340
				Fair Value Measurements Using
	Description	December 31,		Quoted		Significant		Significant		Year Ended
		2012		Prices in		Other		Unobservable		December 31,
				Active		Observable		Inputs		2012
				Markets for		Inputs		(Level 3)		Total
				Identical		(Level 2)				Gains (Losses)
				Assets
				(Level  1)
	Assets held for sale	$	300	$	—	$	—	$	300	$	—
	The measurement of the assets held for sale at fair value incorporated significant unobservable inputs as a result of a lack of any available observable market information to determine the fair value. The calculation of the fair value of assets held for sale used a market valuation technique that relied on Level 3 inputs, including quoted prices for similar assets. In 2012, the Company signed an agreement to sell the assets for $695,000, net of disposal costs. All assets were transferred and sold to the purchaser as of December 31, 2013 and the Company recognized net gains of $340,000, which are included as other income (expenses), net in the statement of comprehensive loss for the year ended December 31, 2013.

Property_Plant_and_Equipment

Property, Plant and Equipment	12 Months Ended
	Dec. 31, 2013
Property Plant And Equipment [Abstract]	'
Property, Plant and Equipment	'
	6. Property, Plant and Equipment
	Property and equipment are recorded at cost. Expenditures for major additions and improvements are capitalized, and maintenance and repairs are charged to expense as incurred. When property and equipment are retired or otherwise disposed of, the cost and accumulated depreciation are removed from the accounts and any resulting gain or loss is included in the results of operations for the respective period. Depreciation is provided over the estimated useful lives of the related assets using the straight-line method. The estimated useful lives for significant property and equipment categories are as follows:
	Office and laboratory equipment	3 years
	Computer equipment and software	3 years
	Leasehold improvements	Term of lease agreement
	The following is a summary of property and equipment at cost less accumulated depreciation as of December 31, 2013 and 2012 (in thousands):
		December 31,			December 31,
		2013			2012
	Laboratory equipment	$	2,299		$	3,149
	Leasehold improvements		616			602
	Computer and software		299			361
	Furniture and fixtures		81			180
	Construction in progress		149			—
			3,444			4,292
	Less: Accumulated depreciation and amortization		(2,476	)		(3,042	)
		$	968		$	1,250
	Depreciation and amortization expense for the years ended December 31, 2013 and 2012 was $0.5 million for each year.

Total_Accrued_and_Other_Curren

Total Accrued and Other Current Liabilities	12 Months Ended
	Dec. 31, 2013
Payables And Accruals [Abstract]	'
Total Accrued and Other Current Liabilities	'
	7. Total Accrued and Other Current Liabilities
	Other current liabilities include the following as of December 31, 2013 and 2012 (in thousands):
		December 31,		December 31,
		2013		2012
	Accrued payroll and related expenses	$	1,481	$	1,220
	Accrued consulting expense		207		122
	Accrued legal and patent expense		124		87
	Accrued sales and excise tax		71		60
	Accrued royalty expense		65		118
	Accrued collaborative research obligations		46		22
	Accrued audit fees		—		73
	Accrued property and equipment		11		27
	Other current liabilities		198		224
	Total accrued and other current liabilities	$	2,203	$	1,953

Concentration_of_Credit_Risk

Concentration of Credit Risk	12 Months Ended
	Dec. 31, 2013
Risks And Uncertainties [Abstract]	'
Concentration of Credit Risk	'
	8. Concentration of Credit Risk
	Revenues from the following distributor and large laboratory customers represented a significant portion of total revenue for the years ended December 31, 2013 and 2012 and accounts receivable as of December 31, 2013 and 2012.
		Revenue						Accounts Receivable
		December 31,			December 31,			December 31,			December 31,
		2013			2012			2013			2012
	Customer A		44	%		44	%		36	%		34	%
	Customer B		14	%		13	%		11	%		14	%
	Customer C		10	%		6	%		10	%		2	%
	Customer D		6	%		6	%		15	%		10	%
	Customer E		5	%		6	%		9	%		10	%
	Total		79	%		75	%		81	%		70	%

Notes_Payable

Notes Payable	12 Months Ended
	Dec. 31, 2013
Debt Disclosure [Abstract]	'
Notes Payable	'
	9. Notes Payable
	In September 2011, the Company entered into a Loan and Security Agreement with Comerica Bank to borrow up to $5 million, the entire amount of which was borrowed at a rate of 5.25% per annum (“Original Term Loan”). The loan was payable in 36 monthly installments which were to begin in October 2012, with interest only payments being made from October 2011 to September 2012. The Company paid an initial fee of $25,000 for access to this loan and will be required to pay an additional fee of $100,000 following repayment of the loan. The Company may prepay all, but not less than all, of the loaned amount with 30 days advance notice to the bank. In connection with the loan, the Company issued a warrant to the bank to purchase 480,769 shares of the Company’s common stock (Note 13).
	The term loan is secured by a first priority security interest on all of the Company’s assets excluding the Company’s intellectual property (except for rights to payment related to the sale, licensing or disposition of such intellectual property rights) and property not assignable without consent by a third party or with respect to which granting a security interest is contrary to law. In addition, the Company has agreed not to sell, assign, transfer, pledge or otherwise encumber its intellectual property to another entity without the bank’s approval or consent, subject to certain exceptions.
	The Loan and Security Agreement contains customary representations and warranties, covenants, events of defaults and termination provisions. The affirmative covenants included, among other things, that the Company timely file taxes, maintain good standing and government compliance, maintain a liquidity ratio of not less than 1.25 to 1, ensure its cumulative net loss does not exceed $6 million beginning July 1, 2013 in accordance with GAAP, maintain primary depository and operating accounts with the bank, maintain liability and other insurance, and provide security interests to the bank in the collateral of any subsidiary formed or acquired by the Company in the future. The negative covenants provided and continue to provide, among other things, that without the prior consent of the bank, the Company may not dispose of certain assets, engage in certain business combinations or acquisitions, incur additional indebtedness or encumber any of the Company’s property (subject to certain exceptions), pay dividends on the Company’s capital stock or make prohibited investments. The loan and security agreement provides that an event of default will occur if, among other triggers, (1) the Company defaults in the payment of any amount payable under the agreement when due, (2) there occurs any circumstance or circumstances that could reasonably be expected to result in a material adverse effect on the Company’s business, operations or condition, or on the Company’s ability to perform its obligations under the agreement, (3) the Company becomes insolvent, (4) the Company undergoes a change in control or (5) the Company breaches any negative covenants or certain affirmative covenants in the agreement or, subject to a cure period, otherwise neglects to perform or observe any material item in the agreement. The repayment of the term loan may be accelerated, at the option of the bank, following the occurrence of an event of default, which would require the Company to pay to the bank an amount equal to the sum of: (i) all outstanding principal plus accrued interest, (ii) the final payment, plus (iii) all other sums, that shall have become due and payable but have not been paid, including interest at the default rate with respect to any past due amounts. As of December 31, 2013, the Company was in compliance with all the covenants.
	On September 11, 2012, the Company and Comerica Bank entered into an Amended and Restated Loan and Security Agreement (the “First Amended Loan and Security Agreement”). The First Amended Loan and Security Agreement extended the interest-only payment period for an additional twelve months, through September 23, 2013, and extended the maturity date for an additional twelve months, to September 23, 2016. The First Amended Loan and Security Agreement also reduced the monthly principal payments by amortizing the loan over a 48 month basis, resulting in an increased balloon payment of principal on the maturity date. The Company paid a fee of $50,000 for access to the First Amended Loan and Security Agreement. Pursuant to the Amendment, the Company issued a warrant to Comerica to purchase 168,919 shares of its common stock. The warrant has an exercise price of $0.37 per share and will expire on September 11, 2019 (Note 13).
	The Company accounted for this amendment as a debt modification since the terms of the original and the First Amended Loan and Security Agreements were not substantially different, and the present value of cash flows of the modified instrument was within 10% of the cash flows of the original debt instrument. Accordingly, debt discount of $48,000 associated with the First Amended Loan and Security Agreement, and unamortized debt discount of $72,000 from the Original Term Loan, is amortized as an adjustment of interest expense over the term of the First Amended Loan and Security Agreement using the effective interest method.
	In October 2013, the Company and Comerica Bank entered into a Second Amended and Restated Loan and Security Agreement (the “Second Amended Loan and Security Agreement”). The Second Amended Loan and Security Agreement increased the aggregate principal amount of the loan by $5 million, the entire amount of which was borrowed on October 17, 2013, for a total outstanding principal amount of $10 million, with interest at a fixed per annum rate equal to 6.45%. The Second Amended Loan and Security Agreement also extends the interest-only payment period for an additional three months, through December 31, 2013, and extends the maturity date for an additional three months, to December 1, 2016. The Second Amended Loan and Security Agreement also reduces the monthly principal payments by amortizing the loan over a 42 month basis, resulting in an increased balloon payment of principal on the maturity date. Additionally, the Company is required to (i) maintain a liquidity ratio of not less than 1.25 to 1 and (ii) ensure its cumulative net loss does not exceed $6 million beginning July 1, 2013 in accordance with GAAP. The Company paid a fee of $50,000 for access to the Second Amended Loan and Security Agreement. Pursuant to the Second Amended Loan and Security Agreement, the Company issued a warrant to Comerica Bank to purchase 96,685 shares of its common stock. The warrant has an exercise price of $1.81 per share and will expire on October 17, 2020 (Note 13).
	The Company accounted for this Second Amended Loan and Security Agreement as a debt modification since the terms of the original and the amended Loan and Security Agreements were not substantially different.
	The Company recorded debt discount of $136,000 associated with the Second Amended Loan and Security Agreement, and unamortized debt discount of $77,000 from the Original Term Loan will be amortized as an adjustment of interest expense over the term of the Second Amended Loan and Security Agreement using the effective interest method.
	Future minimum payments for the notes payable are as follows (in thousands):
	2014	$	3,418
	2015		3,233
	2016		4,728
	Total minimum payments		11,379
	Less: Amount representing interest		(1,379	)
	Present value of minimum payments		10,000
	Less: Unamortized debt discount		(190	)
	Notes payable, net		9,810
	Less: Notes payable, current portion		(2,763	)
	Non-current portion of notes payable	$	7,047

Common_Stock

Common Stock	12 Months Ended
	Dec. 31, 2013
Text Block [Abstract]	'
Common Stock	'
	10. Common Stock
	On July 15, 2011, the Company amended its certificate of incorporation to increase the number of authorized shares of its common stock, par value of $0.01 per share, to 100,000,000. The holders of common stock are entitled to receive dividends, as, when and if declared by the Company’s Board of Directors out of funds legally available for distribution, subject to the restriction on dividends contained in the Company’s Second Amended Loan and Security Agreement with Comerica bank (Note 9).

Basic_and_Diluted_Loss_per_Sha

Basic and Diluted Loss per Share	12 Months Ended
	Dec. 31, 2013
Earnings Per Share [Abstract]	'
Basic and Diluted Loss per Share	'
	11. Basic and Diluted Loss per Share
	Basic net loss per common share is based on the weighted average number of common shares outstanding during the period. Diluted net loss per common share is based on the weighted average number of common shares and other dilutive securities outstanding during the period, provided that including these dilutive securities do not increase the net loss per share.
	The effect of the options and warrants was anti-dilutive for the years ended December 31, 2013 and 2012. The following table shows the total outstanding securities considered anti-dilutive and therefore, excluded from the computation of diluted net loss per share (in thousands):
		As of
		December 31,
		2013		2012
	Options to purchase common stock		9,705		8,963
	Warrants to purchase common stock		266		650
	Restricted stock units		42		—
	Total		10,013		9,613

Stock_Based_Compensation

Stock Based Compensation	12 Months Ended
	Dec. 31, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'
Stock Based Compensation	'
	12. Stock Based Compensation
	Stock Option Plans
	2012 Equity Incentive Award Plan
	The Company’s stockholders approved the 2012 Equity Incentive Award Plan (the “2012 Plan”) at the 2012 Annual Meeting of Stockholders on May 17, 2012 and approved 3,000,000 shares of common stock authorized for issuance. Upon approval of the 2012 Plan, all shares of common stock that remained available for issuance under the 1996 Stock Option Plan (the “1996 Plan”) and the 1998 Director Stock Option Plan (the “Director Plan”) were added to the shares reserved under the 2012 Plan. In addition, pursuant to the 2012 Plan, any shares of common stock subject to awards previously granted under the 1996 Plan, the Director Plan and certain non-plan option agreements entered into with certain individuals as of March 31, 2012 that terminate, expire or lapse will become available for issuance under the 2012 Plan. The 2012 Plan provides for the granting of options, restricted stock awards, restricted stock unit award, performance awards, dividend equivalents awards, deferred stock awards, deferred stock unit awards, stock payment awards and stock appreciation rights to employees, non-employee directors and consultants. Options granted under the 2012 Plan may be designated as qualified or nonqualified at the discretion of the Compensation Committee of the Board of Directors. Generally, shares issuable upon exercise of options vest ratably over four years, beginning one year from the date of grant; however, options can vest upon grant. Option terms expire no later than 10 years from the date of grant, or 5 years from the date the option is granted to a greater than 10% stockholder. The stock options are exercisable at not less than the fair market value of the stock at the date of grant, or not less than 110% of the fair market value of the stock at the date of grant if granted to a greater than 10% stockholder. The Company has also granted restricted stock unit (“RSU”) awards under the 2012 Plan. RSU awards entitle the recipient to receive one share of the Company’s common stock for every RSU upon vesting. RSUs generally vest annually. As of December 31, 2013, options to purchase 3,030,612 shares of common stock were outstanding, 41,708 shares of common stock were issuable upon the settlement of outstanding RSUs and 2,345,617 shares were available for issuance under the 2012 Plan.
	1996 Stock Option Plan
	The 1996 Plan initially had 4,750,000 shares of common stock authorized for issuance and a provision that automatically increased this number by 3.5% of the issued and outstanding common stock on the last trading day of the December immediately preceding each fiscal year through January 2007. Options granted under the 1996 Plan were designated as qualified or nonqualified at the discretion of the Compensation Committee of the Board of Directors. Generally, shares issuable upon exercise of options vest ratably over four years, beginning one year from the date of grant; however, options could vest upon grant. All options expire no later than 10 years from the date of grant. Qualified stock options are exercisable at not less than the fair market value of the stock at the date of grant, and nonqualified stock options are exercisable at prices determined at the discretion of the Board of Directors, but not less than 85% of the fair market value of the stock at the date of grant. On May 17, 2012, the 1996 Plan was terminated in connection with the effectiveness of the 2012 Plan. All 1,555,492 shares that were available for issuance under the 1996 Plan were transferred to the 2012 Plan, and the 6,398,904 shares that were subject to awards outstanding under the 1996 Plan remained outstanding pursuant to the terms of the 1996 Plan. As of December 31, 2013, options to purchase 2,998,554 shares of common stock were outstanding pursuant to the terms of the 1996 Plan.
	1998 Director Stock Option Plan
	The Director Plan for non-employee directors had 300,000 shares of common stock authorized for issuance. On May 17, 2012, the Director Plan was terminated in connection with the effectiveness of the 2012 Plan. All 130,000 shares that were available for issuance under the Director Plan were transferred to the 2012 Plan, and the 170,000 shares that were subject to awards outstanding under the Director Plan remained outstanding pursuant to the terms of the Director Plan. As of December 31, 2013, options to purchase 40,000 shares of common stock were outstanding pursuant to the terms of the Director Plan.
	Non-Plan Grants
	In October 2004, the Company granted non-qualified stock options to purchase 30,000 shares of common stock outside of the Company’s stock option plans to its former director with an exercise price of $12.27 per share. These options were granted with terms that are substantially in accordance with the Company’s standard stock option terms. As of December 31, 2013, all of these options remained outstanding.
	In September 2011, the Company granted non-qualified stock options to purchase 1,530,000 shares of common stock outside of the Company’s stock option plans to its current Chief Executive Officer with an exercise price of $0.25 per share. These options were granted with terms that are substantially in accordance with the Company’s standard stock option terms. As of December 31, 2013, all of these options remained outstanding.
	In October 2011, the Company granted non-qualified stock options to purchase 1,130,000 shares of common stock outside of the Company’s stock option plans to its current Chief Business Officer with an exercise price of $0.26 per share. These options were granted with terms that are substantially in accordance with the Company’s standard stock option terms. As of December 31, 2013, 1,018,458 of these options remained outstanding.
	On February 1, 2012, the Company granted non-qualified stock options to purchase 1,060,000 shares of common stock outside of the Company’s stock option plans to its current Chief Financial Officer with an exercise price of $0.28 per share. These options were granted with terms that are substantially in accordance with the Company’s standard stock option terms. As of December 31, 2013, 1,057,460 of these options remained outstanding.
	Restricted Stock Units
	On August 6, 2013, the Company awarded an aggregate of 41,708 RSUs to its directors with a grant-date fair value equal to approximately $55,000 in the aggregate. Each RSU entitles the recipient to receive one share of the Company’s common stock upon vesting. RSUs awarded to directors generally vest annually. The fair value of nonvested RSUs is based on the Company’s closing stock price on the date of grant. As of December 31, 2013, all of these RSUs remained outstanding and none was vested. A summary for the year ended December 31, 2013 is as follows:
		Shares of			Average Grant			Weighted		Aggregate
		Underlying			Date Fair Value			Remaining Vesting		Intrinsic
		RSUs			Price per Share			Period		Value
								(In years)
	Nonvested as of December 31, 2012		—			—
	Granted		41,708			1.33
	Vested and released		—			—
	Nonvested as of December 31, 2013		41,708		$	1.33			0.5	$	37,537
	Stock Based Compensation Expense
	The following table summarizes stock compensation expense related to employee stock options and employee stock-based compensation expense for the years ended December 31, 2013 and 2012 which was incurred as follows (in thousands):
		Years Ended
		December 31,
		2013			2012
	Stock-based compensation expense:
	General and administrative	$	361		$	204
	Research and development		135			73
	Sales and marketing		113			73
	Product costs		23			12
	Total stock-based compensation expense	$	632		$	362
	Valuation Assumptions
	The compensation expense related to stock options recognized was determined using the Black-Scholes option valuation model. Option valuation models require the input of subjective assumptions and these assumptions can vary over time. The weighted average assumptions used were as follows:
		Years ended
		December 31,
		2013			2012
	Dividend yield		0	%		0	%
	Risk-free interest rate		0.93	%		0.54	%
	Expected volatility		84.66	%		95.97	%
	Forfeiture rate		13.9	%		13.24	%
	Expected term (years)		4.06			4.12
	Fair value per share at grant date	$	0.61		$	0.21
	The expected stock price volatility assumption was determined by examining the historical volatilities for industry peers, and the trading history for the Company’s common stock. For the year ended December 31, 2012, volatility assumption was determined by examining historical volatilities for industry peers only as the Company did not have sufficient trading history for the Company’s common stock for that period. The Company will continue to analyze its own historical stock price volatility as more historical data for the Company’s common stock becomes available. The risk-free interest rate assumption is based on the US Treasury instruments whose term was consistent with the expected term of the Company’s stock options. The expected dividend assumption is based on the Company’s history and expectation of dividend payouts. Different estimates of volatility and expected term could materially change the value of an option and the resulting expense. The expected term of stock options represents the weighted-average period the stock options are expected to remain outstanding. The Company considers option vesting terms, contractual terms and historical information to develop reasonable expectations about future exercise patterns and post-vesting employment termination behavior.
	Employee Stock-Based Compensation
	The table below presents information related to stock option activity, net of options previously exercised:
		Number of			Weighted-			Weighted-		Aggregate
		Options			Average			Average		Intrinsic
		Outstanding			Exercise			Remaining		Value
					Price			Contractual
								Term
								(In years)
	Outstanding as of December 31, 2011		9,187,589		$	0.48
	Options granted		2,669,190			0.32
	Options exercised		(2,247,419	)		0.26
	Options cancelled/forfeited/expired		(646,134	)		0.72
	Outstanding as of December 31, 2012		8,963,226			0.47
	Options granted		1,563,910			1
	Options exercised		(664,568	)		0.26
	Options cancelled/forfeited/expired		(157,484	)		4.53
	Outstanding as of December 31, 2013		9,705,084		$	0.5			7.92	$	5,112,805
Exercisable as of December 31, 2013		5,544,395		$	0.49			7.5	$	3,251,337
Vested and expected to vest as of December 31, 2013		9,097,437		$	0.5			7.88	$	4,863,083
The following table summarizes information relating to stock options outstanding as of December 31, 2013:
	Options Outstanding								Options Exercisable
Range of Exercise Price	Number			Weighted			Weighted		Number		Weighted
	Outstanding			Average			Average		Exercisable		Average
				Remaining			Exercise				Exercise
				Contractual			Price				Price
				Life (In Years)
$0.14		51,000			7.95		$	0.14		27,500	$	0.14
$0.25		1,542,000			7.74			0.25		864,583		0.25
$0.26		2,463,115			7.06			0.26		1,945,198		0.26
$0.28		1,131,710			8.1			0.28		513,668		0.28
$0.29 – $0.33		1,092,647			7.52			0.3		936,395		0.3
$0.34		330,000			8.72			0.34		330,000		0.34
$0.36		1,160,920			8.6			0.36		403,733		0.36
$0.39 – $0.77		978,692			8.57			0.57		295,818		0.44
$1.19 – $12.27		915,000			9.3			1.63		187,500		3.06
$15.71		40,000			0.4			15.71		40,000		15.71
$0.14 – $15.71		9,705,084			7.92		$	0.5		5,544,395	$	0.49
The estimated fair value of grants of stock options to non-employees of the Company is charged to expense in the financial statements. These options vest in the same manner as the employee options granted under the option plan as described above.
Stock based compensation expense recognized during the years ended December 31, 2013 and 2012 includes compensation expense for stock based awards granted to employees based on the grant date fair value estimated in accordance with the provisions of ASC 718. As of December 31, 2013, the total remaining unrecognized cost of approximately $1.0 million is expected to be recognized over approximately two years.
Shares Reserved for Future Issuance
The Company had reserved shares of common stock for future issuance as of December 31, 2013 and 2012 as follows:
	As of December 31,
	2013			2012
Options to purchase common stock		9,705,084			8,963,226
Warrants to purchase common stock		265,604			649,688
Restricted stock units		41,708			—
Shares available for option grants		2,345,617			3,793,751
Total		12,358,013			13,406,665

Stock_Warrants

Stock Warrants	12 Months Ended
	Dec. 31, 2013
Equity [Abstract]	'
Stock Warrants	'
	13. Stock Warrants
	The Company issues warrants to investors as part of its overall financing strategy and to vendors in order to reduce costs. In connection with the loan and security agreement the Company entered into with Comerica bank (Note 9) in September 2011, the Company issued a warrant to purchase 480,769 shares of the Company’s common stock, at an exercise price of $0.26 per share. The warrant expires in September 2018. The initial fair value of the warrant was calculated using the Black-Scholes option pricing model and the following assumptions: volatility of 88.03%, risk-free interest rate of 1.36%, exercise price of $0.26 and an expected life of 7 years. The fair value of the warrant was determined to be $94,000 and was recorded as equity in additional paid-in-capital and a discount to the carrying value of the loan. Through August 2012, the discount was amortized to interest expense using the effective interest rate method over the 48-month term of the original loan. As of September 2012, and in connection with the First Amended and Restated Loan and Security Agreement between the Company and Comerica Bank (Note 9), the unamortized discount will be recognized over the remaining term of the amended loan, which matures in September 2016. Comerica exercised this warrant in August 2013.
	In connection with the First Amended Loan and Security Agreement, the Company issued a warrant to purchase 168,919 shares of the Company’s common stock, at an exercise price of $0.37 per share. This warrant expires in September 2019. The initial fair value of the warrant was calculated using the Black-Scholes option pricing model and the following assumptions: volatility of 89.87%, risk-free interest rate of 1.03%, exercise price of $0.37 and an expected life of 7 years. The fair value of the warrant was determined to be $48,000 and was recorded as equity in additional paid-in-capital and a discount to the carrying value of the loan. The discount is being amortized to interest expense using the effective interest rate method over the remaining term of the amended loan which matures in September 2016.
	In connection with the Second Amended Loan and Security Agreement the Company issued a warrant to purchase 96,685 shares of the Company’s common stock, at an exercise price of $1.81 per share. This warrant expires in October 2020. The initial fair value of the warrant was calculated using the Black-Scholes option pricing model and the following assumptions: volatility of 89.01%, risk-free interest rate of 2.05%, exercise price of $1.81 and an expected life of 7 years. The fair value of the warrant was determined to be $136,000 and was recorded as equity in additional paid-in-capital and a discount to the carrying value of the loan. The discount is being amortized to interest expense using the effective interest rate method over the remaining term of the amended loan which matures in December 2016.
	In August 2013, the Company issued 386,784 shares of common stock pursuant to a cashless exercise of Comerica’s warrant to purchase 480,769 shares at an exercise price of $0.26 per share. As of December 31, 2013, there were warrants outstanding to purchase 265,604 shares of the Company’s common stock, with a weighted-average exercise price of $0.89 per share and an aggregate exercise price of $0.2 million.
	The following table summarizes information about all warrants outstanding as of December 31, 2013:
		Warrants Outstanding and Exercisable
	Exercise Price	Number		Weighted		Weighted
		Outstanding		Average		Average
				Remaining		Exercise
				Contractual		Price
				Life (In Years)
	$0.37		168,919		5.7	$	0.37
	$1.81		96,685		6.8	$	1.81
			265,604		6.1	$	0.89

Leases_Commitments_and_Conting

Leases, Commitments and Contingencies	12 Months Ended
	Dec. 31, 2013
Commitments And Contingencies Disclosure [Abstract]	'
Leases, Commitments and Contingencies	'
	14. Leases, Commitments and Contingencies
	The Company leases an office and laboratory facility (the “349 Facility”) under a long-term, non-cancelable operating lease agreement, which expires in December 2016. The Company also leased another office and laboratory facility (the “343 Facility”), and subleased a portion of that facility, until the Company’s underlying lease for that facility expired on January 1, 2012. Upon expiration of the 343 Facility lease, restricted cash of $400,000 previously pledged as security for this lease was released in 2012.
	In connection with its leased facilities, the Company recognized a liability for asset retirement obligations representing the present value of estimated remediation costs to be incurred at the expiration of the 349 Facility lease. The following table describes changes to the Company’s asset retirement obligation liability for the years ended December 31, 2013 and 2012 (in thousands):
		Years Ended December 31,
		2013		2012
	Asset retirement obligation, beginning of year	$	302	$	273
	Accretion expense		32		29
	Asset retirement obligation, end of year	$	334	$	302
	In 2010, the Company recorded a lease obligation associated with the 349 Facility, which contained a lease payment that exceeded current market rates. Accordingly, the Company recognized a $4.1 million unfavorable lease obligation in 2010. The Company amortizes the unfavorable lease obligation using the effective interest rate method. The carrying amount, net of accumulated amortization, of the unfavorable lease liability, was $2.5 million as of December 31, 2013.
	Rent expense for the Company’s facilities was $1.9 million and $2.0 million for the years ended December 31, 2013 and 2012, respectively. The terms of the lease for the 349 Facility provides for rental payments on a graduated scale. The Company recognizes rent expense on a straight-line basis over the lease period. Deferred rent of $387,000 and $363,000 as of December 31, 2013 and 2012, respectively, is included in the accompanying balance sheet.
	At December 31, 2013, future minimum lease payments under non-cancelable operating leases are as follows (in thousands):
		Operating
		Leases
	2014		2,581
	2015		2,658
	2016		2,738
	Total minimum lease payments	$	7,977
	Legal Proceedings
	The Company is from time to time subject to various claims and legal actions during the ordinary course of business. The Company believes that there are currently no claims or legal actions that would reasonably be expected to have a material adverse effect on its results of operations, future cash flows or financial condition.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2013
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	15. Income Taxes
	Provision for Income Tax
	The Company files US Federal and California state tax returns and the tax provision is composed as follows (in thousands):
		December 31,
		2013			2012
	Current Tax Expense:
	Federal	$	—		$	—
	State		5			2
	Total current tax expense		5			2
	Deferred Tax Expense:
	Federal		—			—
	State		—			—
	Total deferred tax expense		—			—
	Net tax provision (benefit)	$	5		$	2
	The differences between the US statutory tax rate and the Company’s effective tax rate are as follows:
		December 31,
		2013			2012
	Statutory rate		34	%		34	%
	State taxes, net of Federal benefit		11.5			34.9
	Change in state rate		(22.9	)		(36.7	)
	R&D credit		(7.3	)		(33.4	)
	Permanent differences		(3.6	)		(3.4	)
	State minimum taxes		(0.3	)		(0.1	)
	Change in valuation allowance		(13.5	)		2.9
	Other		1.9			1.7
	Effective tax rate		(0.2	)%		(0.1	)%
	As of December 31, 2013, the Company had approximately $232 million of federal, $163 million of California, and $17 million of other state net operating loss carryforwards available to offset future taxable income. These loss carryforwards begin to expire in 2019 for federal purposes, in 2016 for California purposes and in 2014 for other state purposes.
	As of December 31, 2013, the Company had credit carryforwards of approximately $5.8 million and $5.9 million available to reduce future taxable income, if any, for federal and California state income tax purposes, respectively. The federal R&D credit carryforwards expire starting 2019 and California credits can be carried forward indefinitely.
	The effects of changes in tax rates and laws are recognized in the period new legislation is enacted. Furthermore, the reinstatement of an expired provision in a later reporting period requires companies to wait until the date the law is enacted to reflect the effect of the tax law changes into the annual estimated effective tax rate starting on the first interim reporting period that includes the enactment date. The impact of this change, on both the annual effective tax rate and on deferred taxes are to be reported as a component of tax expense related to continuing operations. Although the Company incurred qualified research expenses in 2012 that would generate a federal R&D credit, the deferred tax benefit of these credits is not recorded because the federal provisions extending the R&D credit were not extended until January 2013. Therefore, the amount of federal R&D credits for 2012 was considered a discrete item during the first quarter of 2013 for financial reporting purposes.
	Based on the weight of available evidence, including cumulative losses since inception and expected future losses, the Company has determined that it is more likely than not that the deferred tax asset amount will not be realized and therefore a full valuation allowance has been provided on net deferred tax assets.
	As of December 31, 2013 and 2012, the Company had deferred tax assets of approximately $109.4 million and $109.2 million, respectively, which have been fully offset by a valuation allowance. The net valuation allowance increased by approximately $0.2 million in the year ended December 31, 2013 and decreased by approximately $2.8 million during the year ended December 31, 2012. Deferred tax assets primarily relate to net operating loss and research tax credit carryforwards.
	The tax effects of temporary differences and carryforwards that give rise to deferred tax assets are as follows (in thousands):
		December 31,
		2013			2012
	Deferred tax assets:
	Accruals and reserves	$	1,694		$	1,794
	Fixed assets		2,338			2,563
	Deferred research expense		3,667			5,592
	Stock options		3,822			3,798
	Net operating loss carryforwards		89,306			86,663
	Research tax credit carryforwards		8,541			8,796
	Other		9			7
	Total deferred tax assets		109,377			109,213
	Less: Valuation allowance		(109,377	)		(109,213	)
	Net deferred tax assets	$	—		$	—
	Under the provisions of Sections 382 and 383 of the Internal Revenue Code, a change of control, as defined, may impose an annual limitation on the amount of the Company’s net operating loss and tax credit carryforwards, and other tax attributes, that can be used to reduce future tax liabilities. As a result of the Reverse Merger, certain of the Company’s Old diaDexus tax attributes are subject to an annual limitation of $240,000 for federal and state purposes.
	Uncertain Tax Positions
	Effective January 1, 2009, the Company adopted ASC 740-10 (formerly known as FIN 48), Accounting for Income Taxes, guidance that addresses the recognition, measurement, and disclosure of uncertain tax positions. The Company performed a full analysis of uncertain tax positions at December 31, 2010. The Company has no new uncertain tax positions for 2013.
	As of December 31, 2012, the Company had approximately $1.4 million of unrecognized tax benefits relating to the reserve on R&D credits. In 2013, this amount was increased by $0.2 million as the result of a reserve placed on California R&D credit carryforwards from tax years ended December 31, 2013. As the Company has not utilized any of these credits, no reserve is recorded on the financial statements.
	The following table reflects the changes in the gross unrecognized tax benefits for the years ended December 31 (in thousands):
		2013			2012
	Balance at January 1	$	1,375		$	1,366
	Increase related to gross up state positions		251			—
	Increase related to current year positions		34			—
	Increase related to prior year positions		1			9
	Decrease related to expiration of credits		(93	)		—
	Balance at December 31	$	1,568		$	1,375
	The Company is currently not subject to any income tax examinations. Due to the Company’s losses, generally all years remain open.

Subsequent_Events

Subsequent Events	12 Months Ended
	Dec. 31, 2013
Subsequent Events [Abstract]	'
Subsequent Events	'
	16. Subsequent Events
	In March 2014, the Company and Thermo Fisher Scientific, Inc. (“Thermo Fisher Scientific”) entered into a License and Supply Agreement (the “Agreement”) to develop and commercialize three independent biomarkers in the United States. Upon execution of the Agreement, the Company is obligated to pay Thermo Fisher Scientific an upfront payment of €750,000 and another €500,000 is payable within twelve months of the effective date. In addition, the Company agreed to pay Thermo Fisher Scientific milestone payments, depending on the achievement of future milestone events, including development and regulatory milestone payments.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2013
Earnings Per Share [Abstract]	'
Basis of Presentation	'
	Basis of Presentation
	The accompanying financial statements have been prepared in accordance with US generally accepted accounting principles (“GAAP”). Certain amounts previously reported in the financial statements have been reclassified to conform to the current year presentation. Such reclassifications did not affect net loss, stockholders’ equity or cash flow.
	Starting in January 2013, the Company includes excise tax collected from customer product sales. The Company recognized $402,000 and $455,000 in charged excise tax within product revenue and product costs, respectively, for the year ended December 31, 2013. For the year ended December 31, 2012, there was no excise tax recognized within product revenue and product costs.
Use of Estimates	'
	Use of Estimates
	The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets, including assets held for sale, and liabilities at the date of the financial statements and the reported amount of revenues and expenses during the reporting period. Actual results may differ significantly from those estimates.
	The Company considers the accounting policies related to revenue recognition, stock-based compensation, and income taxes to be the most critical accounting policies, because they require the Company to make estimates, assumptions and judgments about matters that are inherently uncertain.
Cash and Cash Equivalents	'
	Cash and Cash Equivalents
	The Company considers all highly liquid investments purchased with original maturities of 90 days or less to be cash equivalents. Cash equivalents consist primarily of money market accounts and treasury securities.
Restricted Cash	'
	Restricted Cash
	Restricted cash represents term deposits, which expire in December 2016, held at one financial institution as collateral for the lease of the Company’s facilities in South San Francisco.
Available-for-Sale Investments	'
	Available-for-Sale Investments
	The Company classifies its investments as available-for-sale. Available-for-sale investments are recorded at fair value based on quoted market prices, with the unrealized gains or losses included in accumulated other comprehensive income (loss) within stockholders’ equity, except that any unrealized losses which are deemed to be other than temporary are reflected in the statement of operations. Management assesses each of these investments on an individual basis to determine if the decline in fair value was other than temporary. The amortized cost of debt securities is adjusted for amortization of premiums and accretion of discounts to maturity. Such amortization or accretion is included in interest income. Realized gains or losses on sales of available-for-sale securities are reported in other income or expenses as incurred. The cost of securities sold is based on the specific identification method. Interest and dividends on available-for-sale securities are recorded in interest and other income.
Inventory	'
	Inventory
	Inventories are stated as the lower of cost or market. Cost is determined using the first in, first out method. Market value is determined as the lower of replacement cost or net realizable value.
Property and Equipment	'
	Property and Equipment
	Property and equipment are recorded at cost and depreciated over their estimated useful lives using the straight-line method. Laboratory equipment, computers, software, and office furniture are depreciated over three years. Leasehold improvements are recorded at cost and amortized over the term of the lease or their useful life, whichever is shorter. Maintenance and repairs are expensed as incurred.
Segments	'
	Segments
	The Company has one reportable segment and uses one measurement of profitability to manage its business. All long-lived assets are maintained in the United States of America.
	Revenues by geography are based on the billing address of the customer.
Revenue Recognition	'
	Revenue Recognition
	Revenues are generated from product sales, royalties earned, license fees and contract arrangements, and recorded net of customer and distributor discounts. Revenue is recognized when the four basic criteria of revenue recognition are met: (i) a contractual agreement exists; (ii) delivery of product has occurred and risk of loss and title has transferred, transfer of technology (intellectual property) has been completed or services have been rendered; (iii) the fee is fixed or determinable; and (iv) collectability is reasonably assured.
	License fee revenue including nonrefundable upfront fees, is deferred and recognized over the term of the underlying agreements. Royalty revenue is recognized when reportable product sales are confirmed. Revenue from technology licenses or other payments under collaborative agreements where the Company has a continuing obligation to perform is recognized as revenue over the expected period of the continuing performance obligation. The term of these underlying agreements ranges from two to ten years.
Accruals	'
	Accruals
	In connection with the process of preparing financial statements, the Company estimates accrued expenses. This process involves communicating with our applicable personnel to identify services that have been performed on the Company’s behalf and estimating the level of service performed and the associated cost incurred for the service when the Company has not yet been invoiced or otherwise notified of actual cost. The majority of our service providers invoice us monthly in arrears for services performed. The Company makes estimates of accrued expenses as of each balance sheet date in the financial statements based on known facts and circumstances. The Company periodically confirms the accuracy of estimates with selected service providers and makes adjustments, if necessary.
Research and Development	'
	Research and Development
	Research and development expenses include internal and external costs. Internal costs include product development, regulatory support for technology, laboratory materials and supply costs and other technical support costs, including salaries and consultant fees. External expenses consist of sponsored research studies and investigator sponsored trials. Research and development costs are expensed as incurred.
Impairment of Long-Lived Assets	'
	Impairment of Long-Lived Assets
	In accordance with Accounting Standards Codification (“ASC”) Subtopic ASC 360-10, impairment of long-lived assets is measured or assessed when events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable. Determination of recoverability is based on an estimate of undiscounted future cash flows resulting from the use of the asset and its eventual disposition. In the event that such cash flows are not expected to be sufficient to recover the carrying amount of the assets, the assets are written down to their estimated fair values. Long-lived assets to be disposed of are reported at the lower of carrying amount or fair value less costs to sell.
Stock-Based Compensation	'
	Stock-Based Compensation
	The Company recognizes stock-based compensation expense for all stock-based payment awards in accordance with ASC 718, which requires the measurement and recognition of compensation expense for all stock-based payments made to employees and directors including employee stock option awards, based on estimated fair value. Stock-based compensation expense for expected-to-vest stock-based awards is valued under the single-option approach and amortized on a ratable basis, net of estimated forfeitures. The value of the portion of the award that is ultimately expected to vest is recognized as expense over the requisite service periods in the Company’s statements of operations for all periods presented.
	The assumptions used in computing the fair value of stock-based awards reflect the Company’s best estimates, but involve uncertainties relating to market and other conditions, many of which are outside of the Company’s control. In addition, the Company’s estimate of future stock-based compensation expense will be affected by a number of items including the Company’s stock price, the number of stock options the Company’s board of directors may grant in future periods, as well as a number of complex and subjective valuation adjustments and the related tax effect.
	The fair value of nonvested restricted stock units (“RSUs”) is based on the Company’s closing stock price on the date of grant.
	The net loss for the years ended December 31, 2013 and 2012 include employee stock-based compensation expense of $632,000 and $362,000, respectively. As of December 31, 2013, the total unrecorded stock-based compensation expense for unvested stock options, net of expected forfeitures, was $1.0 million, which is expected to be amortized over a weighted-average period of 2.24 years.
Fair Value Measurements	'
	Fair Value Measurements
	In accordance with ASC Subtopic 820-10 the carrying amounts of certain financial instruments of the Company, including cash equivalents, marketable securities and liabilities, continue to be valued at fair value. ASC Subtopic 820-10 defines fair value and provides guidance for using fair value to measure assets and liabilities and is applicable whenever assets or liabilities are required or permitted to be measured at fair value.
	The fair value estimates presented reflect the information available to the Company as of December 31, 2013. See Note 3, “Fair Value Measurements.”
Deferred Rent	'
	Deferred Rent
	Deferred rent consists of the difference between cash payments and the recognition of rent expense on a straight-line basis for the buildings the Company leases. The leases provide for fixed increases in minimum annual rental payments and the total amount of rental payments due over the lease terms are being charged to rent expense ratably over the life of the leases.
Comprehensive Income (Loss)	'
	Comprehensive Income (Loss)
	Comprehensive income (loss) represents all changes in stockholders’ equity except those resulting from investments or contributions by stockholders. The Company’s unrealized gains on available-for-sale securities represent the component of comprehensive income (loss) excluded from the Company’s net loss.
Income Taxes	'
	Income Taxes
	The Company accounts for income taxes under the asset and liability method. Under this method, deferred tax assets and liabilities are determined based on the difference between financial statement and tax bases of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to affect taxable income. Valuation allowances are established when necessary to reduce deferred tax assets to the amounts expected to be realized.
	On January 1, 2009, the Company adopted ASC 740-10-25. For the years ended December 31, 2013 and 2012, the Company did not have any additional unrecognized tax benefits and there was no effect on its financial condition or results of operations as a result of adopting ASC 740-10-25. The Company’s practice is to recognize interest and/or penalties related to income tax matters in interest expense as incurred.
Recent Accounting Pronouncements	'
	Recent Accounting Pronouncements
	In July 2013, Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2013-11, “Presentation of an Unrecognized Tax Benefit when a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists (a consensus of the FASB Emerging Issues Task Force).” The amendments in this ASU provide guidance on the financial statements presentation of an unrecognized tax benefit when a net operating loss carryforward, a similar tax loss, or a tax credit carryforward exists. An unrecognized tax benefit should be presented in the financial statements as a reduction to a deferred tax asset for a net operating loss carryforward, a similar tax loss, or a tax credit carryforward with certain exceptions, in which case such an unrecognized tax benefit should be presented in the financial statements as a liability. The amendments in this ASU do not require new recurring disclosures and are effective for fiscal years, and interim periods within those years, beginning after December 15, 2013. We are currently assessing the impact of this ASU on our financial statements.
Basic and Diluted Net Loss per Common Share	'
	Basic net loss per common share is based on the weighted average number of common shares outstanding during the period. Diluted net loss per common share is based on the weighted average number of common shares and other dilutive securities outstanding during the period, provided that including these dilutive securities do not increase the net loss per share.

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2013
Accounting Policies [Abstract]	'
Schedule of Revenues by Geographic Area	'
	The following table sets forth revenues by geographic area (in thousands):
		Years Ended December 31,
		2013		2012
	United States	$	24,316	$	20,443
	Europe		330		245
	Rest of the world		238		88
		$	24,884	$	20,776

Cash_Cash_Equivalents_and_Inve1

Cash, Cash Equivalents and Investments (Tables)	12 Months Ended
	Dec. 31, 2013
Cash And Cash Equivalents [Abstract]	'
Cash, Cash Equivalents, and Available-for-Sale Securities	'
	The following is a summary of cash, cash equivalents, and available-for-sale securities as of December 31, 2013 and 2012 (in thousands):
		December 31, 2013
		Cost Basis		Unrealized		Unrealized		Estimated
				Gains		Losses		Fair Value
	Cash and cash equivalents:
	Cash	$	12,800	$	—	$	—	$	12,800
	Money market funds		4,047		—		—		4,047
	Total cash and cash equivalents	$	16,847	$	—	$	—	$	16,847
		December 31, 2012
		Cost Basis		Unrealized		Unrealized		Estimated
				Gains		Losses		Fair Value
	Cash and cash equivalents:
	Cash	$	6,054	$	—	$	—	$	6,054
	Money market funds		6,797		—		—		6,797
	Total cash and cash equivalents	$	12,851	$	—	$	—	$	12,851
	Available-for-sale marketable securities:
	Certificate of deposits		747		—		—		747
	Total available-for-sale marketable securities	$	747	$	—	$	—	$	747
Fair Value Hierarchy for Financial Assets Measured at Fair Value on Recurring Basis	'
	The following table represents the Company’s fair value hierarchy for its financial assets (cash equivalents and investments) measured at fair value on a recurring basis as of December 31, 2013 and 2012 (in thousands):
				Fair Value Measurements
		Balance as of		Quoted Prices		Significant		Significant
		December 31,		In Active		other		Unobservable
		2013		Markets for		Observable		Inputs
				Identical Assets		Inputs		Level 3
				Level  1		Level 2
	Assets:
	Cash	$	12,800	$	12,800	$	—	$	—
	Money market funds		4,047		4,047		—		—
	Restricted cash		1,400		—		1,400		—
		$	18,247	$	16,847	$	1,400	$	—
				Fair Value Measurements
		Balance as of		Quoted Prices		Significant		Significant
		December 31,		In Active		other		Unobservable
		2012		Markets for		Observable		Inputs
				Identical Assets		Inputs		Level 3
				Level  1		Level 2
	Assets:
	Cash	$	6,054	$	6,054	$	—	$	—
	Money market funds		6,797		6,797		—		—
	Certificates of deposit		747		—		747		—
	Restricted cash		1,400		—		1,400		—
		$	14,998	$	12,851	$	2,147	$	—

Inventory_Tables

Inventory (Tables)	12 Months Ended
	Dec. 31, 2013
Inventory Disclosure [Abstract]	'
Inventory	'
	Inventory consists of the following (in thousands):
		December 31,		December 31,
		2013		2012
	Finished goods	$	361	$	61
	Raw materials		99		73
		$	460	$	134

Assets_Held_For_Sale_Tables

Assets Held For Sale (Tables)	12 Months Ended
	Dec. 31, 2013
Text Block [Abstract]	'
Assets Held for Sale	'
	Total assets held for sale are as follows (in thousands):
				Fair Value Measurements Using
	Description	December 31,		Quoted		Significant		Significant		Year Ended
		2013		Prices in		Other		Unobservable		December 31,
				Active		Observable		Inputs		2013
				Markets for		Inputs		(Level 3)		Total
				Identical		(Level 2)				Gains (Losses)
				Assets
				(Level  1)
	Assets held for sale	$	—	$	—	$	—	$	—	$	340
				Fair Value Measurements Using
	Description	December 31,		Quoted		Significant		Significant		Year Ended
		2012		Prices in		Other		Unobservable		December 31,
				Active		Observable		Inputs		2012
				Markets for		Inputs		(Level 3)		Total
				Identical		(Level 2)				Gains (Losses)
				Assets
				(Level  1)
	Assets held for sale	$	300	$	—	$	—	$	300	$	—

Property_Plant_and_Equipment_T

Property, Plant and Equipment (Tables)	12 Months Ended
	Dec. 31, 2013
Property Plant And Equipment [Abstract]	'
Schedule of Estimated Useful Lives for Significant Property and Equipment	'
	The estimated useful lives for significant property and equipment categories are as follows:
	Office and laboratory equipment	3 years
	Computer equipment and software	3 years
	Leasehold improvements	Term of lease agreement
Property and Equipment at Cost Less Accumulated Depreciation	'
	The following is a summary of property and equipment at cost less accumulated depreciation as of December 31, 2013 and 2012 (in thousands):
		December 31,			December 31,
		2013			2012
	Laboratory equipment	$	2,299		$	3,149
	Leasehold improvements		616			602
	Computer and software		299			361
	Furniture and fixtures		81			180
	Construction in progress		149			—
			3,444			4,292
	Less: Accumulated depreciation and amortization		(2,476	)		(3,042	)
		$	968		$	1,250

Total_Accrued_and_Other_Curren1

Total Accrued and Other Current Liabilities (Tables)	12 Months Ended
	Dec. 31, 2013
Payables And Accruals [Abstract]	'
Accrued and Other Current Liabilities	'
	Other current liabilities include the following as of December 31, 2013 and 2012 (in thousands):
		December 31,		December 31,
		2013		2012
	Accrued payroll and related expenses	$	1,481	$	1,220
	Accrued consulting expense		207		122
	Accrued legal and patent expense		124		87
	Accrued sales and excise tax		71		60
	Accrued royalty expense		65		118
	Accrued collaborative research obligations		46		22
	Accrued audit fees		—		73
	Accrued property and equipment		11		27
	Other current liabilities		198		224
	Total accrued and other current liabilities	$	2,203	$	1,953

Concentration_of_Credit_Risk_T

Concentration of Credit Risk (Tables)	12 Months Ended
	Dec. 31, 2013
Risks And Uncertainties [Abstract]	'
Revenues from Large Laboratory Customers	'
	Revenues from the following distributor and large laboratory customers represented a significant portion of total revenue for the years ended December 31, 2013 and 2012 and accounts receivable as of December 31, 2013 and 2012.
		Revenue						Accounts Receivable
		December 31,			December 31,			December 31,			December 31,
		2013			2012			2013			2012
	Customer A		44	%		44	%		36	%		34	%
	Customer B		14	%		13	%		11	%		14	%
	Customer C		10	%		6	%		10	%		2	%
	Customer D		6	%		6	%		15	%		10	%
	Customer E		5	%		6	%		9	%		10	%
	Total		79	%		75	%		81	%		70	%

Notes_Payable_Tables

Notes Payable (Tables)	12 Months Ended
	Dec. 31, 2013
Debt Disclosure [Abstract]	'
Future Minimum Payments for Notes Payable	'
	Future minimum payments for the notes payable are as follows (in thousands):
	2014	$	3,418
	2015		3,233
	2016		4,728
	Total minimum payments		11,379
	Less: Amount representing interest		(1,379	)
	Present value of minimum payments		10,000
	Less: Unamortized debt discount		(190	)
	Notes payable, net		9,810
	Less: Notes payable, current portion		(2,763	)
	Non-current portion of notes payable	$	7,047

Basic_and_Diluted_Loss_per_Sha1

Basic and Diluted Loss per Share (Tables)	12 Months Ended
	Dec. 31, 2013
Earnings Per Share [Abstract]	'
Outstanding Securities Considered Anti-Dilutive, and Therefore Excluded from Computation of Diluted Net Loss Per Share	'
	The following table shows the total outstanding securities considered anti-dilutive and therefore, excluded from the computation of diluted net loss per share (in thousands):
		As of
		December 31,
		2013		2012
	Options to purchase common stock		9,705		8,963
	Warrants to purchase common stock		266		650
	Restricted stock units		42		—
	Total		10,013		9,613

Stock_Based_Compensation_Table

Stock Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'
Summary of Nonvested Restricted Stock Units	'
	A summary for the year ended December 31, 2013 is as follows:
		Shares of			Average Grant			Weighted		Aggregate
		Underlying			Date Fair Value			Remaining Vesting		Intrinsic
		RSUs			Price per Share			Period		Value
								(In years)
	Nonvested as of December 31, 2012		—			—
	Granted		41,708			1.33
	Vested and released		—			—
	Nonvested as of December 31, 2013		41,708		$	1.33			0.5	$	37,537
Summary of Stock Compensation Expense Related to Employee Stock Options and Employee Stock Based Compensation	'
	The following table summarizes stock compensation expense related to employee stock options and employee stock-based compensation expense for the years ended December 31, 2013 and 2012 which was incurred as follows (in thousands):
		Years Ended
		December 31,
		2013			2012
	Stock-based compensation expense:
	General and administrative	$	361		$	204
	Research and development		135			73
	Sales and marketing		113			73
	Product costs		23			12
	Total stock-based compensation expense	$	632		$	362
Weighted Average Assumptions Used with Regard to Stock Option	'
	The weighted average assumptions used were as follows:
		Years ended
		December 31,
		2013			2012
	Dividend yield		0	%		0	%
	Risk-free interest rate		0.93	%		0.54	%
	Expected volatility		84.66	%		95.97	%
	Forfeiture rate		13.9	%		13.24	%
	Expected term (years)		4.06			4.12
	Fair value per share at grant date	$	0.61		$	0.21
Schedule of Stock Option Activity	'
	The table below presents information related to stock option activity, net of options previously exercised:
		Number of			Weighted-			Weighted-		Aggregate
		Options			Average			Average		Intrinsic
		Outstanding			Exercise			Remaining		Value
					Price			Contractual
								Term
								(In years)
	Outstanding as of December 31, 2011		9,187,589		$	0.48
	Options granted		2,669,190			0.32
	Options exercised		(2,247,419	)		0.26
	Options cancelled/forfeited/expired		(646,134	)		0.72
	Outstanding as of December 31, 2012		8,963,226			0.47
	Options granted		1,563,910			1
	Options exercised		(664,568	)		0.26
	Options cancelled/forfeited/expired		(157,484	)		4.53
	Outstanding as of December 31, 2013		9,705,084		$	0.5			7.92	$	5,112,805
	Exercisable as of December 31, 2013		5,544,395		$	0.49			7.5	$	3,251,337
	Vested and expected to vest as of December 31, 2013		9,097,437		$	0.5			7.88	$	4,863,083
Summary of Information Relating to Stock Options Outstanding	'
	The following table summarizes information relating to stock options outstanding as of December 31, 2013:
		Options Outstanding								Options Exercisable
	Range of Exercise Price	Number			Weighted			Weighted		Number		Weighted
		Outstanding			Average			Average		Exercisable		Average
					Remaining			Exercise				Exercise
					Contractual			Price				Price
					Life (In Years)
	$0.14		51,000			7.95		$	0.14		27,500	$	0.14
	$0.25		1,542,000			7.74			0.25		864,583		0.25
	$0.26		2,463,115			7.06			0.26		1,945,198		0.26
	$0.28		1,131,710			8.1			0.28		513,668		0.28
	$0.29 – $0.33		1,092,647			7.52			0.3		936,395		0.3
	$0.34		330,000			8.72			0.34		330,000		0.34
	$0.36		1,160,920			8.6			0.36		403,733		0.36
	$0.39 – $0.77		978,692			8.57			0.57		295,818		0.44
	$1.19 – $12.27		915,000			9.3			1.63		187,500		3.06
	$15.71		40,000			0.4			15.71		40,000		15.71
	$0.14 – $15.71		9,705,084			7.92		$	0.5		5,544,395	$	0.49
Reserved Shares of Common Stock for Future Issuance	'
	The Company had reserved shares of common stock for future issuance as of December 31, 2013 and 2012 as follows:
		As of December 31,
		2013			2012
	Options to purchase common stock		9,705,084			8,963,226
	Warrants to purchase common stock		265,604			649,688
	Restricted stock units		41,708			—
	Shares available for option grants		2,345,617			3,793,751
	Total		12,358,013			13,406,665

Stock_Warrants_Tables

Stock Warrants (Tables)	12 Months Ended
	Dec. 31, 2013
Equity [Abstract]	'
Summarizes Information about All Warrants Outstanding	'
	The following table summarizes information about all warrants outstanding as of December 31, 2013:
		Warrants Outstanding and Exercisable
	Exercise Price	Number		Weighted		Weighted
		Outstanding		Average		Average
				Remaining		Exercise
				Contractual		Price
				Life (In Years)
	$0.37		168,919		5.7	$	0.37
	$1.81		96,685		6.8	$	1.81
			265,604		6.1	$	0.89

Leases_Commitments_and_Conting1

Leases, Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2013
Commitments And Contingencies Disclosure [Abstract]	'
Summary of Changes in Asset Retirement Obligation Liability of Company	'
	The following table describes changes to the Company’s asset retirement obligation liability for the years ended December 31, 2013 and 2012 (in thousands):
		Years Ended December 31,
		2013		2012
	Asset retirement obligation, beginning of year	$	302	$	273
	Accretion expense		32		29
	Asset retirement obligation, end of year	$	334	$	302
Future Minimum Lease Payments under Non-Cancelable Operating Leases	'
	At December 31, 2013, future minimum lease payments under non-cancelable operating leases are as follows (in thousands):
		Operating
		Leases
	2014		2,581
	2015		2,658
	2016		2,738
	Total minimum lease payments	$	7,977

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2013
Income Tax Disclosure [Abstract]	'
Summary of US Federal and California State Tax Returns and Tax Provision	'
	The Company files US Federal and California state tax returns and the tax provision is composed as follows (in thousands):
		December 31,
		2013			2012
	Current Tax Expense:
	Federal	$	—		$	—
	State		5			2
	Total current tax expense		5			2
	Deferred Tax Expense:
	Federal		—			—
	State		—			—
	Total deferred tax expense		—			—
	Net tax provision (benefit)	$	5		$	2
Differences between US Statutory Tax Rate and Company's Effective Tax Rate	'
	The differences between the US statutory tax rate and the Company’s effective tax rate are as follows:
		December 31,
		2013			2012
	Statutory rate		34	%		34	%
	State taxes, net of Federal benefit		11.5			34.9
	Change in state rate		(22.9	)		(36.7	)
	R&D credit		(7.3	)		(33.4	)
	Permanent differences		(3.6	)		(3.4	)
	State minimum taxes		(0.3	)		(0.1	)
	Change in valuation allowance		(13.5	)		2.9
	Other		1.9			1.7
	Effective tax rate		(0.2	)%		(0.1	)%
Summary of Tax Effects of Temporary Differences and Carryforwards That Give Rise to Deferred Tax Assets	'
	The tax effects of temporary differences and carryforwards that give rise to deferred tax assets are as follows (in thousands):
		December 31,
		2013			2012
	Deferred tax assets:
	Accruals and reserves	$	1,694		$	1,794
	Fixed assets		2,338			2,563
	Deferred research expense		3,667			5,592
	Stock options		3,822			3,798
	Net operating loss carryforwards		89,306			86,663
	Research tax credit carryforwards		8,541			8,796
	Other		9			7
	Total deferred tax assets		109,377			109,213
	Less: Valuation allowance		(109,377	)		(109,213	)
	Net deferred tax assets	$	—		$	—
Summary of Changes in Gross Unrecognized Tax Benefits	'
	The following table reflects the changes in the gross unrecognized tax benefits for the years ended December 31 (in thousands):
		2013			2012
	Balance at January 1	$	1,375		$	1,366
	Increase related to gross up state positions		251			—
	Increase related to current year positions		34			—
	Increase related to prior year positions		1			9
	Decrease related to expiration of credits		(93	)		—
	Balance at December 31	$	1,568		$	1,375

Business_Overview_Additional_I

Business Overview - Additional Information (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2013
In Thousands, unless otherwise specified			Maximum [Member]	Minimum [Member]
			Ratio	Ratio
Schedule Of Description Of Business [Line Items]	'	'	'	'
Liquidity ratio	'	'	1.25	1
Cumulative net loss	($199,896)	($197,732)	$6,000	'

Summary_of_Significant_Account3

Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
	Segment
Accounting Policies [Abstract]	'	'	'
Excise tax recoginzed in product revenue	$402,000	$0	'
Excise tax recognized in product costs	455,000	0	'
Investments considered cash and cash equivalents, maturity period	'90 days or less	'	'
Property plant and equipment useful life	'3 years	'	'
Number of reportable segment	1	'	'
License fee agreement period, Minimum	'2 years	'	'
License fee agreement period, Maximum	'10 years	'	'
Employee stock-based compensation expense	632,000	362,000	'
Total unrecorded stock-based compensation expense	1,000,000	'	'
Unrecorded stock-based compensation expense, weighted average amortization period	'2 years 2 months 27 days	'	'
Unrecognized tax benefits	$1,568,000	$1,375,000	$1,366,000

Summary_of_Significant_Account4

Summary of Significant Accounting Policies - Schedule of Revenues by Geographic Area (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Revenue, Major Customer [Line Items]	'	'
Revenues	$24,884	$20,776
United States [Member]	'	'
Revenue, Major Customer [Line Items]	'	'
Revenues	24,316	20,443
Europe [Member]	'	'
Revenue, Major Customer [Line Items]	'	'
Revenues	330	245
Rest of World [Member]	'	'
Revenue, Major Customer [Line Items]	'	'
Revenues	$238	$88

Cash_Cash_Equivalents_and_Inve2

Cash, Cash Equivalents and Investments - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013
Cash And Cash Equivalents [Abstract]	'
Maturity period of securities	'1 year
Maturity period for all highly liquid investments	'90 days
Notes payable face value	$10

Cash_Cash_Equivalents_and_Inve3

Cash, Cash Equivalents and Investments - Cash, Cash Equivalents, and Available-for-Sale Securities (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Thousands, unless otherwise specified
Cash Cash Equivalents And Short Term Investments [Line Items]	'	'	'
Cash and cash equivalents, Cost Basis	$16,847	$12,851	$10,484
Cash and cash equivalents, Unrealized Gains	'	'	'
Cash and cash equivalents, Unrealized Losses	'	'	'
Cash and cash equivalents, Estimated Fair Value	16,847	12,851	'
Available-for-sale securities, Cost Basis	'	747	'
Available-for-sale securities, Unrealized Gains	'	'	'
Available-for-sale securities, Unrealized Losses	'	'	'
Available-for-sale securities, Estimated Fair Value	'	747	'
Cash [Member]	'	'	'
Cash Cash Equivalents And Short Term Investments [Line Items]	'	'	'
Cash and cash equivalents, Cost Basis	12,800	6,054	'
Cash and cash equivalents, Unrealized Gains	'	'	'
Cash and cash equivalents, Unrealized Losses	'	'	'
Cash and cash equivalents, Estimated Fair Value	12,800	6,054	'
Money market funds [Member]	'	'	'
Cash Cash Equivalents And Short Term Investments [Line Items]	'	'	'
Cash and cash equivalents, Cost Basis	4,047	6,797	'
Cash and cash equivalents, Unrealized Gains	'	'	'
Cash and cash equivalents, Unrealized Losses	'	'	'
Cash and cash equivalents, Estimated Fair Value	4,047	6,797	'
Certificate of deposit [Member]	'	'	'
Cash Cash Equivalents And Short Term Investments [Line Items]	'	'	'
Available-for-sale securities, Cost Basis	'	747	'
Available-for-sale securities, Unrealized Gains	'	'	'
Available-for-sale securities, Unrealized Losses	'	'	'
Available-for-sale securities, Estimated Fair Value	'	$747	'

Cash_Cash_Equivalents_and_Inve4

Cash, Cash Equivalents and Investments - Fair Value Hierarchy for Financial Assets Measured at Fair Value on Recurring Basis (Detail) (Fair value, measurements, recurring [Member], USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets, Fair Value Measurements	$18,247	$14,998
Restricted cash [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets, Fair Value Measurements	1,400	1,400
Certificate of deposit [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets, Fair Value Measurements	'	747
Cash [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets, Fair Value Measurements	12,800	6,054
Money market funds [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets, Fair Value Measurements	4,047	6,797
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets, Fair Value Measurements	16,847	12,851
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] | Restricted cash [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets, Fair Value Measurements	'	'
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] | Certificate of deposit [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets, Fair Value Measurements	'	'
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] | Cash [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets, Fair Value Measurements	12,800	6,054
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] | Money market funds [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets, Fair Value Measurements	4,047	6,797
Significant other Observable Inputs (Level 2) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets, Fair Value Measurements	1,400	2,147
Significant other Observable Inputs (Level 2) [Member] | Restricted cash [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets, Fair Value Measurements	1,400	1,400
Significant other Observable Inputs (Level 2) [Member] | Certificate of deposit [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets, Fair Value Measurements	'	747
Significant other Observable Inputs (Level 2) [Member] | Cash [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets, Fair Value Measurements	'	'
Significant other Observable Inputs (Level 2) [Member] | Money market funds [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets, Fair Value Measurements	'	'
Significant Unobservable Inputs (Level 3) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets, Fair Value Measurements	'	'
Significant Unobservable Inputs (Level 3) [Member] | Restricted cash [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets, Fair Value Measurements	'	'
Significant Unobservable Inputs (Level 3) [Member] | Certificate of deposit [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets, Fair Value Measurements	'	'
Significant Unobservable Inputs (Level 3) [Member] | Cash [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets, Fair Value Measurements	'	'
Significant Unobservable Inputs (Level 3) [Member] | Money market funds [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets, Fair Value Measurements	'	'

Inventory_Inventory_Detail

Inventory - Inventory (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Inventory Disclosure [Abstract]	'	'
Finished goods	$361	$61
Raw materials	99	73
Total inventory	$460	$134

Assets_Held_For_Sale_Assets_He

Assets Held For Sale - Assets Held for Sale (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets held for sale	'	$300
Total Gains (Losses)	340	'
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets held for sale	'	'
Significant other Observable Inputs (Level 2) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets held for sale	'	'
Significant Unobservable Inputs (Level 3) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets held for sale	'	$300

Assets_Held_For_Sale_Additiona

Assets Held For Sale - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Property Plant And Equipment Assets Held For Sale Disclosure [Abstract]	'	'
Committed sales price for assets held for sale	'	$695,000
Gains (losses) on sale of assets	$340,000	($4,000)

Property_Plant_and_Equipment_S

Property, Plant and Equipment - Schedule of Estimated Useful Lives for Significant Property and Equipment (Detail)	12 Months Ended
	Dec. 31, 2013
Property, Plant and Equipment [Line Items]	'
Estimated useful lives	'3 years
Office and laboratory equipment [Member]	'
Property, Plant and Equipment [Line Items]	'
Estimated useful lives	'3 years
Computer equipment and software [Member]	'
Property, Plant and Equipment [Line Items]	'
Estimated useful lives	'3 years
Leasehold improvements [Member]	'
Property, Plant and Equipment [Line Items]	'
Leasehold improvements	'Term of lease agreement

Property_Plant_and_Equipment_P

Property, Plant and Equipment - Property and Equipment at Cost Less Accumulated Depreciation (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Property, Plant and Equipment [Line Items]	'	'
Gross property and equipment	$3,444	$4,292
Less: Accumulated depreciation and amortization	-2,476	-3,042
Total Property, Plant and Equipment	968	1,250
Laboratory equipment [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Gross property and equipment	2,299	3,149
Leasehold improvements [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Gross property and equipment	616	602
Computer equipment and software [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Gross property and equipment	299	361
Furniture and fixtures [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Gross property and equipment	81	180
Construction in progress [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Gross property and equipment	$149	'

Property_Plant_and_Equipment_A

Property, Plant and Equipment - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Property Plant And Equipment [Abstract]	'	'
Depreciation and amortization expense	$0.50	$0.50

Total_Accrued_and_Other_Curren2

Total Accrued and Other Current Liabilities - Accrued and Other Current Liabilities (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Payables And Accruals [Abstract]	'	'
Accrued payroll and related expenses	$1,481	$1,220
Accrued consulting expense	207	122
Accrued legal and patent expense	124	87
Accrued sales and excise tax	71	60
Accrued royalty expense	65	118
Accrued collaborative research obligations	46	22
Accrued audit fees	'	73
Accrued property and equipment	11	27
Other current liabilities	198	224
Total accrued and other current liabilities	$2,203	$1,953

Concentration_of_Credit_Risk_R

Concentration of Credit Risk - Revenues from Large Laboratory Customers (Detail)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Concentration Risk [Line Items]	'	'
Revenue	79.00%	75.00%
Accounts Receivable	81.00%	70.00%
Customer A [Member]	'	'
Concentration Risk [Line Items]	'	'
Revenue	44.00%	44.00%
Accounts Receivable	36.00%	34.00%
Customer B [Member]	'	'
Concentration Risk [Line Items]	'	'
Revenue	14.00%	13.00%
Accounts Receivable	11.00%	14.00%
Customer C [Member]	'	'
Concentration Risk [Line Items]	'	'
Revenue	10.00%	6.00%
Accounts Receivable	10.00%	2.00%
Customer D [Member]	'	'
Concentration Risk [Line Items]	'	'
Revenue	6.00%	6.00%
Accounts Receivable	15.00%	10.00%
Customer E [Member]	'	'
Concentration Risk [Line Items]	'	'
Revenue	5.00%	6.00%
Accounts Receivable	9.00%	10.00%

Notes_Payable_Additional_Infor

Notes Payable - Additional Information (Detail) (USD $)	0 Months Ended	1 Months Ended		12 Months Ended		12 Months Ended		0 Months Ended	12 Months Ended
	Sep. 30, 2011	Aug. 31, 2013	Sep. 30, 2011	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2013	Sep. 30, 2011	Dec. 31, 2013	Dec. 31, 2013	Oct. 17, 2013
				Installment		Minimum [Member]	Maximum [Member]	Notes payable [Member]	First Amended Loan and Security Agreement [Member]	Second Amended Loan and Security Agreement [Member]	Second Amended Loan and Security Agreement [Member]
Debt Instrument [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Proceeds from bank debt	'	'	'	'	'	'	'	$5,000,000	'	'	'
Interest rate on loan	'	'	'	'	'	'	'	5.25%	'	'	'
Period for monthly installment	'	'	'	'Monthly	'	'	'	'	'	'	'
Debt instrument number of installments	'	'	'	36	'	'	'	'	'	'	'
Loan processing fee	'	'	'	25,000	'	'	'	'	'	'	'
Additional fee required	'	'	'	100,000	'	'	'	'	'	'	'
Advance notice period to the bank	'	'	'	'30 days	'	'	'	'	'	'	'
Warrant issued to purchase common stock	480,769	480,769	480,769	'	'	'	'	'	'	'	'
Liquidity ratio	'	'	'	'	'	1.25	'	'	'	'	'
Cumulative net loss	'	'	'	-199,896,000	-197,732,000	'	6,000,000	'	'	'	'
Repayment of term loan description	'	'	'	'The repayment of the term loan may be accelerated, at the option of the bank, following the occurrence of an event of default, which would require the Company to pay to the bank an amount equal to the sum of: (i) all outstanding principal plus accrued interest, (ii) the final payment, plus (iii) all other sums, that shall have become due and payable but have not been paid, including interest at the default rate with respect to any past due amounts. As of December 31, 2013, the Company was in compliance with all the covenants.	'	'	'	'	'	'	'
Extended interest-only payment period	'	'	'	'	'	'	'	'	23-Sep-13	31-Dec-13	'
Amended and Restated Loan and Security, Maturity date	'	'	'	'	'	'	'	'	23-Sep-16	1-Dec-16	'
Monthly principal payments by amortizing the loan	'	'	'	'	'	'	'	'	'48 months	'42 months	'
Amendment access fee	'	'	'	'	'	'	'	'	50,000	50,000	'
Common stock purchase	'	'	'	'	'	'	'	'	168,919	96,685	'
Warrants exercise price per share	'	'	'	'	'	'	'	'	$0.37	$1.81	'
Warrant expiry date	'	'	'	'	'	'	'	'	11-Sep-19	17-Oct-20	'
Present value of modified debt instrument	'	'	'	'	'	'	'	'	10.00%	'	'
Debt discount	'	'	'	'	'	'	'	'	48,000	136,000	'
Unamortized debt discount	'	'	'	190,000	'	'	'	'	72,000	77,000	'
Increase in aggregate principal amount	'	'	'	'	'	'	'	'	'	'	5,000,000
Outstanding principal amount	'	'	'	$10,000,000	'	'	'	'	'	'	$10,000,000
Interest rate on loan	'	'	'	'	'	'	'	'	'	'	6.45%

Notes_Payable_Future_Minimum_P

Notes Payable - Future Minimum Payments for Notes Payable (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Notes Payable [Abstract]	'	'
2014	$3,418	'
2015	3,233	'
2016	4,728	'
Total minimum payments	11,379	'
Less: Amount representing interest	-1,379	'
Present value of minimum payments	10,000	'
Less: Unamortized debt discount	-190	'
Notes payable, net	9,810	'
Less: Notes payable, current portion	-2,763	-272
Non-current portion of notes payable	$7,047	$4,621

Common_Stock_Additional_Inform

Common Stock - Additional Information (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Jul. 15, 2011
Equity [Abstract]	'	'	'
Common stock, shares authorized	100,000,000	100,000,000	100,000,000
Increase in number of authorized shares of common stock, par value	$0.01	$0.01	$0.01

Basic_and_Diluted_Loss_per_Sha2

Basic and Diluted Loss per Share - Outstanding Securities Considered Anti-Dilutive, and Therefore Excluded from Computation of Diluted Net Loss Per Share (Detail)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Total	10,013	9,613
Options to purchase common stock [Member]	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Total	9,705	8,963
Warrants to purchase common stock [Member]	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Total	266	650
Restricted stock units [Member]	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Total	42	'

Stock_Based_Compensation_Addit

Stock Based Compensation - Additional Information (Detail) (USD $)

12 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

12 Months Ended

1 Months Ended

1 Months Ended

1 Months Ended

0 Months Ended

12 Months Ended

In Millions, except Share data, unless otherwise specified

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Aug. 06, 2013

Dec. 31, 2013

Dec. 31, 2013

17-May-12

Dec. 31, 2013

Dec. 31, 2013

17-May-12

Dec. 31, 2013

Oct. 31, 2004

Dec. 31, 2013

Sep. 30, 2011

Dec. 31, 2013

Oct. 31, 2011

Dec. 31, 2013

Feb. 01, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Restricted Stock Units [Member]

Restricted Stock Units [Member]

Restricted Stock Units [Member]

Restricted Stock Units [Member]

1996 Stock Option Plan [Member]

1996 Stock Option Plan [Member]

1996 Stock Option Plan [Member]

1998 Director Stock Option Plan [Member]

1998 Director Stock Option Plan [Member]

1998 Director Stock Option Plan [Member]

Non-Plan Grants [Member]

Non-Plan Grants [Member]

Non-Plan Grants [Member]

Non-Plan Grants [Member]

Non-Plan Grants [Member]

Non-Plan Grants [Member]

Non-Plan Grants [Member]

Non-Plan Grants [Member]

2012 Equity Incentive Award Plan [Member]

2012 Equity Incentive Award Plan [Member]

Director [Member]

Director [Member]

Options to purchase common stock [Member]

Options to purchase common stock [Member]

Director [Member]

Director [Member]

Chief Executive Officer [Member]

Chief Executive Officer [Member]

Chief Business Officer [Member]

Chief Business Officer [Member]

Chief Financial Officer [Member]

Chief Financial Officer [Member]

Options to purchase common stock [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Shares of common stock authorized for issuance

'

'

'

'

'

'

'

'

'

4,750,000

'

'

300,000

'

'

'

'

'

'

'

'

'

3,000,000

Issuable upon exercise of options vest

'

'

'

'

'

'

'

'

'

'4 years

'

'

'

'

'

'

'

'

'

'

'

'4 years

'

Non Employee Stock Options Vesting Period

'1 year

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Options outstanding

9,705,084

8,963,226

9,187,589

'

'

'

'

2,998,554

6,398,904

'

40,000

170,000

'

'

30,000

'

1,530,000

'

1,018,458

'

1,057,460

3,030,612

'

Shares available for grant

2,345,617

3,793,751

'

'

'

'

'

'

'

'

'

'

'

30,000

'

1,530,000

'

1,130,000

'

1,060,000

'

2,345,617

'

Condition for stock option expiry

'Option terms expire no later than 10 years from the date of grant, or 5 years from the date the option is granted to a greater than 10% stockholder

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Condition for stock options exercisable

'Stock options are exercisable at not less than the fair market value of the stock at the date of grant, or not less than 110% of the fair market value of the stock at the date of grant if granted to a greater than 10% stockholder.

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Percentage increased by the number of issued and outstanding common stock

'

'

'

'

'

'

'

'

'

3.50%

'

'

'

'

'

'

'

'

'

'

'

'

'

Options expire from the date of grant

'

'

'

'

'

'

'

'

'

'10 years

'

'

'

'

'

'

'

'

'

'

'

'

'

Period between grant date and vesting period start date

'

'

'

'

'

'

'

'

'

'1 year

'

'

'

'

'

'

'

'

'

'

'

'

'

Determination of Non qualified stock options exercise price fair market value of stock minimum percentage

'

'

'

'

'

'

'

85.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Shares transferred form prior plans available for issuance under the plan

'

'

'

'

'

'

'

'

1,555,492

'

'

130,000

'

'

'

'

'

'

'

'

'

'

'

Stock option plans, exercise price per share

$0.26

$0.26

'

'

'

'

'

'

'

'

'

'

'

$12.27

'

$0.25

'

$0.26

'

$0.28

'

'

'

Restricted Stock Units awarded to directors

'

'

'

'

'

41,708

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Restricted Stock Units, grant-date fair value

'

'

'

'

'

55,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Restricted Stock Units awarded, outstanding

'

'

'

41,708

'

'

41,708

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

RSU entitles the recipient to receive share of the Company's common stock upon vesting

'

'

'

'

'

'

1

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Restricted Stock Units, vested

'

'

'

'

'

'

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total remaining unrecognized cost for stock based compensation

$1

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock based compensation expenses recognition period

'2 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock_Based_Compensation_Summa

Stock Based Compensation - Summary of Nonvested Restricted Stock Units (Detail) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Shares of Underlying RSUs, Granted	12,358,013	13,406,665
Average Grant Date Fair Value Price per Share, Granted	$0.61	$0.21
Restricted Stock Units [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Shares of Underlying RSUs, Nonvested, Beginning balance	'	'
Shares of Underlying RSUs, Granted	41,708	'
Shares of Underlying RSUs, Vested and released	'	'
Shares of Underlying RSUs, Nonvested, Ending balance	41,708	'
Average Grant Date Fair Value Price per Share, Nonvested, Beginning balance	'	'
Average Grant Date Fair Value Price per Share, Granted	$1.33	'
Average Grant Date Fair Value Price per Share, Vested and released	'	'
Average Grant Date Fair Value Price per Share, Nonvested, Ending balance	$1.33	'
Weighted Remaining Vesting Period	'6 months	'
Aggregate Intrinsic Value	$37,537	'

Stock_Based_Compensation_Summa1

Stock Based Compensation - Summary of Stock Compensation Expense Related to Employee Stock Options and Employee Stock Based Compensation (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Stock-based compensation expense:	'	'
Total stock-based compensation expense	$632	$362
General and administrative [Member]	'	'
Stock-based compensation expense:	'	'
Total stock-based compensation expense	361	204
Research and development [Member]	'	'
Stock-based compensation expense:	'	'
Total stock-based compensation expense	135	73
Sales and marketing [Member]	'	'
Stock-based compensation expense:	'	'
Total stock-based compensation expense	113	73
Product costs [Member]	'	'
Stock-based compensation expense:	'	'
Total stock-based compensation expense	$23	$12

Stock_Based_Compensation_Weigh

Stock Based Compensation - Weighted Average Assumptions Used with Regard to Stock Option (Detail) (USD $)	1 Months Ended	12 Months Ended
	Sep. 30, 2011	Dec. 31, 2013	Dec. 31, 2012
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'	'	'
Dividend yield	'	0.00%	0.00%
Risk-free interest rate	1.36%	0.93%	0.54%
Expected volatility	'	84.66%	95.97%
Forfeiture rate	'	13.90%	13.24%
Expected term (years)	'	'4 years 22 days	'4 years 1 month 13 days
Fair value per share at grant date	'	$0.61	$0.21

Stock_Based_Compensation_Sched

Stock Based Compensation - Schedule of Stock Option Activity (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'	'
Number of Options Outstanding, Beginning balance	8,963,226	9,187,589
Weighted-Average Exercise Price, Outstanding Beginning balance	$0.47	$0.48
Number of Options Outstanding, Options granted	1,563,910	2,669,190
Number of Options Outstanding, Options exercised	-664,568	-2,247,419
Number of Options Outstanding, Options cancelled/forfeited/expired	-157,484	-646,134
Number of Options Outstanding, Ending balance	9,705,084	8,963,226
Number of Options Outstanding, Exercisable, Ending balance	5,544,395	'
Number of Options Outstanding, Vested and expected to vest, Ending balance	9,097,437	'
Weighted-Average Exercise Price, Options granted	$1	$0.32
Weighted-Average Exercise Price, Options exercised	$0.26	$0.26
Weighted-Average Exercise Price, Options cancelled/forfeited/expired	$4.53	$0.72
Weighted-Average Exercise Price, Outstanding Ending balance	$0.50	$0.47
Weighted-Average Exercise Price, Exercisable, Ending balance	$0.49	'
Weighted-Average Exercise Price, Vested and expected to vest, Ending balance	$0.50	'
Weighted-Average Remaining Contractual Term, Outstanding, Ending balance	'7 years 11 months 1 day	'
Weighted-Average Remaining Contractual Term, Exercisable, Ending balance	'7 years 6 months	'
Weighted-Average Remaining Contractual Term, Vested and expected to vest, Ending balance	'7 years 10 months 17 days	'
Aggregate Intrinsic Value, Outstanding, Ending balance	$5,112,805	'
Aggregate Intrinsic Value, Exercisable, Ending balance	3,251,337	'
Aggregate Intrinsic Value, Vested and expected to vest, Ending balance	$4,863,083	'

Stock_Based_Compensation_Summa2

Stock Based Compensation - Summary of Information Relating to Stock Options Outstanding (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013
Range One [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Exercise Price Lower Limit	$0.14
Number Outstanding, Options Outstanding	51,000
Weighted Average Remaining Contractual Life, Options Outstanding	'7 years 11 months 12 days
Weighted Average Exercise Price, Options Outstanding	$0.14
Number Exercisable, Options Exercisable	27,500
Weighted Average Exercise Price, Options Exercisable	$0.14
Range Two [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Exercise Price Lower Limit	$0.25
Number Outstanding, Options Outstanding	1,542,000
Weighted Average Remaining Contractual Life, Options Outstanding	'7 years 8 months 27 days
Weighted Average Exercise Price, Options Outstanding	$0.25
Number Exercisable, Options Exercisable	864,583
Weighted Average Exercise Price, Options Exercisable	$0.25
Range Three [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Exercise Price Lower Limit	$0.26
Number Outstanding, Options Outstanding	2,463,115
Weighted Average Remaining Contractual Life, Options Outstanding	'7 years 22 days
Weighted Average Exercise Price, Options Outstanding	$0.26
Number Exercisable, Options Exercisable	1,945,198
Weighted Average Exercise Price, Options Exercisable	$0.26
Range Four [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Exercise Price Lower Limit	$0.28
Number Outstanding, Options Outstanding	1,131,710
Weighted Average Remaining Contractual Life, Options Outstanding	'8 years 1 month 6 days
Weighted Average Exercise Price, Options Outstanding	$0.28
Number Exercisable, Options Exercisable	513,668
Weighted Average Exercise Price, Options Exercisable	$0.28
Range Five [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Exercise Price Lower Limit	$0.29
Exercise Price Upper Limit	$0.33
Number Outstanding, Options Outstanding	1,092,647
Weighted Average Remaining Contractual Life, Options Outstanding	'7 years 6 months 7 days
Weighted Average Exercise Price, Options Outstanding	$0.30
Number Exercisable, Options Exercisable	936,395
Weighted Average Exercise Price, Options Exercisable	$0.30
Range Six [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Exercise Price Lower Limit	$0.34
Number Outstanding, Options Outstanding	330,000
Weighted Average Remaining Contractual Life, Options Outstanding	'8 years 8 months 19 days
Weighted Average Exercise Price, Options Outstanding	$0.34
Number Exercisable, Options Exercisable	330,000
Weighted Average Exercise Price, Options Exercisable	$0.34
Range Seven [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Exercise Price Lower Limit	$0.36
Number Outstanding, Options Outstanding	1,160,920
Weighted Average Remaining Contractual Life, Options Outstanding	'8 years 7 months 6 days
Weighted Average Exercise Price, Options Outstanding	$0.36
Number Exercisable, Options Exercisable	403,733
Weighted Average Exercise Price, Options Exercisable	$0.36
Range Eight [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Exercise Price Lower Limit	$0.39
Exercise Price Upper Limit	$0.77
Number Outstanding, Options Outstanding	978,692
Weighted Average Remaining Contractual Life, Options Outstanding	'8 years 6 months 26 days
Weighted Average Exercise Price, Options Outstanding	$0.57
Number Exercisable, Options Exercisable	295,818
Weighted Average Exercise Price, Options Exercisable	$0.44
Range Nine [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Exercise Price Lower Limit	$1.19
Exercise Price Upper Limit	$12.27
Number Outstanding, Options Outstanding	915,000
Weighted Average Remaining Contractual Life, Options Outstanding	'9 years 3 months 18 days
Weighted Average Exercise Price, Options Outstanding	$1.63
Number Exercisable, Options Exercisable	187,500
Weighted Average Exercise Price, Options Exercisable	$3.06
Range Ten [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Exercise Price Lower Limit	$15.71
Number Outstanding, Options Outstanding	40,000
Weighted Average Remaining Contractual Life, Options Outstanding	'4 months 24 days
Weighted Average Exercise Price, Options Outstanding	$15.71
Number Exercisable, Options Exercisable	40,000
Weighted Average Exercise Price, Options Exercisable	$15.71
Range Eleven [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Exercise Price Lower Limit	$0.14
Exercise Price Upper Limit	$15.71
Number Outstanding, Options Outstanding	9,705,084
Weighted Average Remaining Contractual Life, Options Outstanding	'7 years 11 months 1 day
Weighted Average Exercise Price, Options Outstanding	$0.50
Number Exercisable, Options Exercisable	5,544,395
Weighted Average Exercise Price, Options Exercisable	$0.49

Stock_Based_Compensation_Reser

Stock Based Compensation - Reserved Shares of Common Stock for Future Issuance (Detail)	Dec. 31, 2013	Dec. 31, 2012
Common Stock Capital Shares Reserved For Future Issuance [Line Items]	'	'
Warrants to purchase common stock	265,604	649,688
Shares available for option grants	2,345,617	3,793,751
Options to purchase common stock	12,358,013	13,406,665
Options to purchase common stock [Member]	'	'
Common Stock Capital Shares Reserved For Future Issuance [Line Items]	'	'
Options to purchase common stock	9,705,084	8,963,226
Restricted Stock Units [Member]	'	'
Common Stock Capital Shares Reserved For Future Issuance [Line Items]	'	'
Options to purchase common stock	41,708	'

Stock_Warrants_Additional_Info

Stock Warrants - Additional Information (Detail) (USD $)	0 Months Ended	1 Months Ended		12 Months Ended
	Sep. 30, 2011	Aug. 31, 2013	Sep. 30, 2011	Dec. 31, 2013	Dec. 31, 2012
Class of Warrant or Right [Line Items]	'	'	'	'	'
Warrant issued to purchase common stock	480,769	480,769	480,769	'	'
Exercise price of warrant	'	$0.26	$0.26	'	'
Volatility	'	'	'	84.66%	95.97%
Risk-free interest rate	'	'	1.36%	0.93%	0.54%
Expected life of warrant	'	'	'7 years	'	'
Fair value of warrant	'	'	$94,000	'	'
Warrant expiry date	'	'	'	'2018-09	'
Warrants Outstanding and Exercisable, Number	'	'	'	265,604	'
Warrants Outstanding and Exercisable, Weighted Average Exercise Price	'	'	'	0.89	'
Common stock issued	'	386,784	'	'	'
Warrants outstanding [Member]	'	'	'	'	'
Class of Warrant or Right [Line Items]	'	'	'	'	'
Volatility	'	'	88.03%	'	'
Discount being amortized to interest expense	'	'	'	'48 months	'
Warrants Outstanding and Exercisable, Number	'	'	'	265,604	'
Warrants Outstanding and Exercisable, Weighted Average Exercise Price	'	'	'	0.89	'
Aggregate exercise price	'	'	'	200,000	'
Warrants to purchase common stock [Member] | First Amended Loan and Security Agreement [Member]	'	'	'	'	'
Class of Warrant or Right [Line Items]	'	'	'	'	'
Warrant issued to purchase common stock	'	'	'	168,919	'
Exercise price of warrant	'	'	'	$0.37	'
Volatility	'	'	'	89.87%	'
Risk-free interest rate	'	'	'	1.03%	'
Expected life of warrant	'	'	'	'7 years	'
Fair value of warrant	'	'	'	48,000	'
Warrant expiry date	'	'	'	'2019-09	'
Warrants to purchase common stock [Member] | Second Amended Loan and Security Agreement [Member]	'	'	'	'	'
Class of Warrant or Right [Line Items]	'	'	'	'	'
Warrant issued to purchase common stock	'	'	'	96,685	'
Exercise price of warrant	'	'	'	$1.81	'
Volatility	'	'	'	89.01%	'
Risk-free interest rate	'	'	'	2.05%	'
Expected life of warrant	'	'	'	'7 years	'
Fair value of warrant	'	'	'	$136,000	'
Warrant expiry date	'	'	'	'2020-10	'
Loan, maturity date	'	'	'	31-Dec-16	'
Amended and Restated Loan and Security Agreement [Member]	'	'	'	'	'
Class of Warrant or Right [Line Items]	'	'	'	'	'
Loan, maturity date	'	'	'	30-Sep-16	'

Stock_Warrants_Summarizes_Info

Stock Warrants - Summarizes Information about All Warrants Outstanding (Detail)	12 Months Ended
	Dec. 31, 2013
Class of Warrant or Right [Line Items]	'
Warrants Outstanding and Exercisable, Number	265,604
Warrants Outstanding and Exercisable, Weighted Average Remaining Contractual Life (In Years)	'6 years 1 month 6 days
Warrants Outstanding and Exercisable, Weighted Average Exercise Price	0.89
Warrant 0.37 [Member]	'
Class of Warrant or Right [Line Items]	'
Warrants Outstanding and Exercisable, Number	168,919
Warrants Outstanding and Exercisable, Weighted Average Remaining Contractual Life (In Years)	'5 years 8 months 12 days
Warrants Outstanding and Exercisable, Weighted Average Exercise Price	0.37
Warrant 1.81 [Member]	'
Class of Warrant or Right [Line Items]	'
Warrants Outstanding and Exercisable, Number	96,685
Warrants Outstanding and Exercisable, Weighted Average Remaining Contractual Life (In Years)	'6 years 9 months 18 days
Warrants Outstanding and Exercisable, Weighted Average Exercise Price	1.81

Leases_Commitments_and_Conting2

Leases, Commitments and Contingencies - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2010
Commitments Contingencies And Litigation [Line Items]	'	'	'
Lease expiration date	'2016-12	'	'
Sub lease expiration date	1-Jan-12	'	'
Unfavorable lease obligation expense	'	'	$4,100,000
Net of accumulated amortization	2,500,000	'	'
Rent expense	1,900,000	2,000,000	'
Deferred rent	387,000	363,000	'
343 Facility lease [Member]	'	'	'
Commitments Contingencies And Litigation [Line Items]	'	'	'
Restricted cash released	$400,000	'	'

Leases_Commitments_and_Conting3

Leases, Commitments and Contingencies - Summary of Changes in Asset Retirement Obligation Liability of Company (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Asset Retirement Obligation Disclosure [Abstract]	'	'
Asset retirement obligation, beginning of year	$302	$273
Accretion expense	32	29
Asset retirement obligation, end of year	$334	$302

Leases_Commitments_and_Conting4

Leases, Commitments and Contingencies - Future Minimum Lease Payments under Non-Cancelable Operating Leases (Detail) (USD $)	Dec. 31, 2013
In Thousands, unless otherwise specified
Commitments And Contingencies Disclosure [Abstract]	'
2014	$2,581
2015	2,658
2016	2,738
Total minimum lease payments	$7,977

Income_Taxes_Summary_of_US_Fed

Income Taxes - Summary of US Federal and California State Tax Returns and Tax Provision (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Current Tax Expense:	'	'
Federal	'	'
State	5	2
Total current tax expense	5	2
Deferred Tax Expense:	'	'
Federal	'	'
State	'	'
Total deferred tax expense	'	'
Net tax provision (benefit)	$5	$2

Income_Taxes_Differences_betwe

Income Taxes - Differences between US Statutory Tax Rate and Company's Effective Tax Rate (Detail)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]	'	'
Statutory rate	34.00%	34.00%
State taxes, net of Federal benefit	11.50%	34.90%
Change in state rate	-22.90%	-36.70%
R&D credit	-7.30%	-33.40%
Permanent differences	-3.60%	-3.40%
State minimum taxes	-0.30%	-0.10%
Change in valuation allowance	-13.50%	2.90%
Other	1.90%	1.70%
Effective tax rate	-0.20%	-0.10%

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Operating Loss Carryforwards [Line Items]	'	'	'
Deferred tax assets	$109,377,000	$109,213,000	'
Net valuation allowance	200,000	2,800,000	'
Merger tax attribute annual limitations for federal and state purpose	240,000	'	'
Uncertain tax positions	0	'	'
Unrecognized tax benefits	1,568,000	1,375,000	1,366,000
Domestic Tax Authority [Member]	'	'	'
Operating Loss Carryforwards [Line Items]	'	'	'
Operating Loss Carryforwards	232,000,000	'	'
Credit carryforwards	5,800,000	'	'
Expiration period of net operating loss carryforwards	'2019	'	'
California [Member]	'	'	'
Operating Loss Carryforwards [Line Items]	'	'	'
Operating Loss Carryforwards	163,000,000	'	'
Credit carryforwards	5,900,000	'	'
Expiration period of net operating loss carryforwards	'2016	'	'
Unrecognized tax benefits increased amount, Gross	200,000	'	'
State and Local Jurisdiction [Member]	'	'	'
Operating Loss Carryforwards [Line Items]	'	'	'
Operating Loss Carryforwards	$17,000,000	'	'
Expiration period of net operating loss carryforwards	'2014	'	'

Income_Taxes_Summary_of_Tax_Ef

Income Taxes - Summary of Tax Effects of Temporary Differences and Carryforwards That Give Rise to Deferred Tax Assets (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Deferred tax assets:	'	'
Accruals and reserves	$1,694	$1,794
Fixed assets	2,338	2,563
Deferred research expense	3,667	5,592
Stock options	3,822	3,798
Net operating loss carryforwards	89,306	86,663
Research tax credit carryforwards	8,541	8,796
Other	9	7
Total deferred tax assets	109,377	109,213
Less: Valuation allowance	-109,377	-109,213
Net deferred tax assets	'	'

Income_Taxes_Summary_of_Change

Income Taxes - Summary of Changes in Gross Unrecognized Tax Benefits (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]	'	'
Balance at January 1	$1,375	$1,366
Increase related to gross up state positions	251	'
Increase related to current year positions	34	'
Increase related to prior year positions	1	9
Decrease related to expiration of credits	-93	'
Balance at December 31	$1,568	$1,375

Subsequent_Events_Additional_I

Subsequent Events - Additional Information (Detail) (Thermo Fisher Scientific [Member], Subsequent Event [Member], EUR €)	12 Months Ended
	Mar. 31, 2014
Thermo Fisher Scientific [Member] | Subsequent Event [Member]	'
Subsequent Event [Line Items]	'
Upfront payment	€ 750,000
Upfront milestone payable amount	€ 500,000