Biocept (BIOCQ) 10-K 17 Apr 23 2022 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Apr. 13, 2023	Jun. 30, 2022
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2022
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	FY
Trading Symbol	BIOC
Entity Registrant Name	Biocept, Inc.
Entity Central Index Key	0001044378
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding			17,777,185
Entity Public Float				$ 15,907,495
Document Annual Report	true
Document Transition Report	false
Entity File Number	001-36284
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	80-0943522
Entity Address, Address Line One	9955 Mesa Rim Road
Entity Address, City or Town	San Diego
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	92121
City Area Code	858
Local Phone Number	320-8200
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Security Exchange Name	NASDAQ
Entity Shell Company	false
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
ICFR Auditor Attestation Flag	false
Auditor Name	RSM US LLP	Mayer Hoffman McCann P.C.
Auditor Location	Dallas, Texas	San Diego, California
Auditor Firm ID	49	199

Balance Sheets

Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Current assets:
Cash	$ 12,897	$ 28,864
Accounts receivable	2,151	13,786
Inventories, net	757	2,651
Prepaid expenses and other current assets	538	391
Total current assets	16,343	45,692
Fixed assets, net	2,572	2,401
Lease right-of-use asset - operating	8,486	9,026
Lease right-of-use assets - finance	3,086	2,842
Other non-current assets	386	456
Total assets	30,873	60,417
Current liabilities:
Accounts payable	1,523	7,246
Accrued liabilities	2,249	3,018
Current portion of lease liability - operating	518	426
Current portion of lease liabilities - finance	1,099	1,083
Supplier financing	117
Total current liabilities	5,506	11,773
Non-current portion of lease liability - operating	9,175	9,736
Non-current portion of lease liabilities - finance	1,200	1,428
Payor liability	6,132
Total liabilities	22,013	22,937
Commitments and contingencies (see Note 13)
Stockholders' equity:
Preferred stock, $0.0001 par value, 5,000,000 shares authorized; 2,090 shares and 2,106 shares issued and outstanding at December 31, 2022 and 2021, respectively.
Common stock, $0.0001 par value, 150,000,000 shares authorized; 17,070,071 shares and 16,849,805 shares issued and outstanding at December 31, 2022 and 2021, respectively.	2	2
Additional paid-in capital	307,296	303,829
Accumulated deficit	(298,438)	(266,351)
Total stockholders' equity	8,860	37,480
Total liabilities and stockholders' equity	$ 30,873	$ 60,417

Balance Sheets (Parenthetical)

Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	2,090	2,106
Preferred stock, shares outstanding	2,090	2,106
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	17,070,071	16,849,805
Common stock, shares outstanding	17,070,071	16,849,805

Statements of Operations

Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Income Statement [Abstract]
Net revenues	$ 25,858	$ 61,249
Costs and expenses:
Cost of revenues	28,440	37,764
Research and development expenses	6,161	4,960
General and administrative expenses	16,113	12,614
Sales and marketing expenses	7,127	8,320
Total costs and expenses	57,841	63,658
Loss from operations	(31,983)	(2,409)
Other (expense):
Interest expense, net	(316)	(290)
Other income, net	87
Total other (expense):	(229)	(290)
Loss before income taxes	(32,212)	(2,699)
Income tax benefit (expense)	125	(125)
Net loss	(32,087)	(2,824)
Net loss attributable to common shareholders	$ (32,087)	$ (2,824)
Weighted-average shares outstanding used in computing net loss per share attributable to common shareholders:
Basic	16,953,812	14,775,805
Diluted	16,953,812	14,775,805
Net loss per common share:
Basic	$ (1.89)	$ (0.19)
Diluted	$ (1.89)	$ (0.19)

Statements of Shareholders' Equ

Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Common Stock [Member] Cashless Warrants [Member]	Series A Convertible Preferred Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]
Beginning balance at Dec. 31, 2020	$ 23,692	$ 1			$ 287,218	$ (263,527)
Beginning balance, shares at Dec. 31, 2020		13,397,041		2,111
Stock-based compensation expense	2,462				2,462
Shares issued upon exercise/cashless exercise of common stock warrants	28				28
Shares issued upon exercise/cashless exercise of common stock warrants		7,212	16,200
Shares and warrants issued, net of issuance costs	14,120	$ 1			14,119
Shares and warrants issued, net of issuance costs, shares		3,428,680
Shares issued upon exercise of stock options	$ 2				2
Shares issued upon exercise of stock options, Shares	537	537
Shares issued upon conversion of preferred stock, shares		135		(5)
Net loss	$ (2,824)					(2,824)
Ending balance at Dec. 31, 2021	37,480	$ 2			303,829	(266,351)
Ending balance, shares at Dec. 31, 2021		16,849,805		2,106
Stock-based compensation expense	3,227				3,227
Shares and warrants issued, net of issuance costs	240				240
Shares and warrants issued, net of issuance costs, shares		219,910
Shares issued upon conversion of preferred stock, shares		356		(16)
Net loss	(32,087)					(32,087)
Ending balance at Dec. 31, 2022	$ 8,860	$ 2			$ 307,296	$ (298,438)
Ending balance, shares at Dec. 31, 2022		17,070,071		2,090

Statements of Cash Flows

Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Cash Flows from Operating Activities
Net loss	$ (32,087)	$ (2,824)
Adjustments to reconcile net loss to net cash (used in) provided by operating activities:
Depreciation and amortization	1,655	1,530
Noncash operating lease expense	540	1,107
Stock-based compensation	3,227	2,462
Loss on disposal of fixed assets	9	4
Non-cash credit card rewards	82
Increase (decrease) in cash resulting from changes in:
Accounts receivable	11,636	358
Inventory	1,894	(721)
Landlord reimbursement		1,856
Prepaid expenses and other current assets	693	505
Other non-current assets	28	(29)
Accounts payable	(5,860)	(411)
Accrued liabilities	(770)	(147)
Operating lease liability	(468)
Payor liability	6,132
Net cash (used in) provided by operating activities	(13,289)	3,690
Cash Flows from Investing Activities:
Purchases of fixed assets	(807)	(1,572)
Net cash used in investing activities	(807)	(1,572)
Cash Flows from Financing Activities:
Net proceeds from issuance of common stock	240	14,120
Proceeds from exercise of common stock warrants		28
Proceeds from exercise of stock options		2
Payments on finance leases	(1,305)	(1,150)
Payments on supplier financing	(806)	(622)
Net cash (used in) provided by financing activities	(1,871)	12,378
Net (decrease) increase in cash	(15,967)	14,496
Cash at Beginning of Period	28,864	14,368
Cash at End of Period	12,897	28,864
Supplemental Disclosures of Cash Flow Information:
Cash paid for interest	316	290
Non-cash Investing and Financing Activities
Financed insurance premiums	893	622
Fixed assets purchased under finance lease obligations	1,049	1,237
Unpaid fixed asset purchases	$ 137	$ 240

The Company and Business Activi

The Company and Business Activities	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
The Company and Business Activities	1. The Company and Business Activities Biocept, Inc., the Company, was founded in California in May 1997 and is a molecular oncology diagnostics company that develops and commercializes proprietary circulating tumor cell and circulating cell-free tumor DNA and RNA assays utilizing a standard blood sample, or liquid biopsy. The Company’s current and planned assays are intended to provide information to aid healthcare providers to identify specific oncogenic alterations that may qualify a subset of cancer patients for targeted therapy at diagnosis, progression or for monitoring to identify specific resistance mechanisms. Sometimes traditional procedures, such as surgical tissue biopsies, result in tumor tissue that is insufficient and/or unable to provide the molecular subtype information necessary for clinical decisions. The Company’s assays, performed on blood and cerebral spinal fluid, have the potential to provide more contemporaneous information on the characteristics of a patient’s disease when compared with tissue biopsy and radiographic imaging. Further, sales to laboratory supply distributors of the Company’s proprietary SCTs commenced in June 2018, which allow for the intact transport of liquid biopsy samples for research use only, or RUO, from regions around the world. The Company operates a clinical laboratory that is CLIA-certified (under the Clinical Laboratory Improvement Amendment of 1988) and CAP-accredited (by the College of American Pathologists), and manufactures cell enrichment and extraction microfluidic channels, related equipment and certain reagents to perform the Company’s diagnostic assays in a facility located in San Diego, California. CLIA certification and accreditation are required before any clinical laboratory may perform testing on human specimens for the purpose of obtaining information for the diagnosis, prevention, treatment of disease, or assessment of health. The assays the Company offers are classified as laboratory developed tests under the CLIA regulations. In July 2013, the Company effected a reincorporation to Delaware by merging itself with and into Biocept, Inc., a Delaware corporation, which had been formed to be and was a wholly-owned subsidiary of the Company since July 23, 2013. The Company experienced increased revenue levels in 2022 and 2021 related to its COVID-19 testing business. I n February, 2023, due to reduced demand, the Company ceased COVID-19 testing services.

Liquidity

Liquidity	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
Liquidity	2. Liquidity As of December 31, 2022 , cash totaled $ 12.9 million, and the Company had an accumulate d deficit of $ 298.4 million . For the years ended December 31, 2022 and 2021 , the Company incurred net losses of $ 32.1 million and $ 2.8 million, respectively. The Company has historically funded its operations primarily through sales of its equity securities. During the year ended December 31, 2022, net revenues were approximately $ 25.9 million compared with approximately $ 61.2 million for the same period in the prior year. For the year ended December 31, 2021, revenue from the Company’s COVID-19 testing business provided an increased level of cash flow. I n February 2023, the Company ceased COVID-19 testing services. The Company incurred operating losses for the year ended December 31, 2022 and 2021. The Company had net cash used to fund operations for the year ended December 31, 2022, and net cash provided by operations for the year ended December 31, 2021. The Company does not anticipate it will be profitable until, if ever, it has commercial expansion of its proprietary clinical diagnostic laboratory assays designed to identify rare tumor cells from cerebrospinal fluid, trademarked as CNSide. Accordingly, management performed the required going concern assessment and determined substantial doubt exists about the Company's ability to continue as a going concern within one year after the issuance date of this Annual Report on Form 10-K. We currently expect that our existing resources will only be sufficient to fund our planned operations and expenditures into the third quarter of 2023. Management intends to continue its efforts to contain costs, reducing staff, and to raise additional capital until it ultimately generates sufficient cash to support operations from commercial sales. Management’s plans are based on events that are not within its control and therefore substantial doubt about the Company’s ability to continue as a going concern has not been alleviated.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	3. Summary of Significant Accounting Policies Basis of Presentation The accompanying financial statements and notes are prepared in accordance with accounting principles generally accepted in the United States of America, or U.S. GAAP, and are prepared on the basis that the Company will continue as a going concern (see Note 2). The accompanying financial statements and notes do not include any adjustments to reflect the possible future effects on the recoverability and classification of assets or the amounts and classification of liabilities that may result from the possible inability of the Company to continue as a going concern. Reclassification The Company reclassified the change in inventory reserve for the year ended December 31, 2021 of approximately $ 0.1 million within the statement of cash flows to conform to the current year presentation. The change in inventory reserve is now included in the increase (decrease) in cash resulting from changes in inventory within the cash flows from operating activities. This reclassification had no effect on previously reported cash flows from operating activities in the statement of cash flows. Going Concern The Company assesses and determines its ability to continue as a going concern in accordance with the provisions of ASC Topic 205-40, Presentation of Financial Statements—Going Concern, which requires the Company to evaluate whether there are conditions or events that raise substantial doubt about its ability to continue as a going concern within one year after the date that its annual and interim financial statements are issued (see Note 2). Certain additional financial statement disclosures are required if such conditions or events are identified. If and when an entity’s liquidation becomes imminent, financial statements should be prepared under the liquidation basis of accounting. Determining the extent, if any, to which conditions or events raise substantial doubt about the Company’s ability to continue as a going concern, or the extent to which mitigating plans sufficiently alleviate any such substantial doubt, as well as whether or not liquidation is imminent, requires significant judgment by management. Use of Estimates The preparation of financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. On an ongoing basis, management evaluates these estimates and judgments, including those related to accounts receivable reserves, inventory reserves, long-lived asset impairment and useful lives, income taxes, including uncertain tax benefits, estimated transaction price for revenues, stock-based compensation, incremental borrowing rate estimates, and the determination of the Company’s ability to continue as a going concern. The Company bases its estimates on various assumptions that it believes are reasonable under the circumstances. Actual results may differ from these estimates under different assumptions or conditions. Revenue Recognition and Accounts Receivable The Company's commercial revenues are generated from diagnostic services provided to patient’s physicians and billed to third-party insurance payors such as managed care organizations, Medicare and Medicaid and patients for any deductibles, coinsurance or copayments that may be due. The Company recognizes revenue in accordance with ASC 606, Revenue from Contracts with Customers, which requires that an entity recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled to in exchange for those goods or services. Contracts For its commercial revenues, while the Company markets directly to physicians and other healthcare providers, the Company provides services that benefit the patient. Patients do not typically enter into direct agreements with the Company; however, a patient’s insurance coverage requirements would dictate whether or not any portion of the cost of the tests would be patient responsibility. Accordingly, the Company establishes contracts with commercial insurers in accordance with customary business practices, as follows: • Approval of a contract is established via the order and accession, which are submitted by the patient’s physician. • The Company is obligated to perform its diagnostic services upon receipt of a sample from a physician, and the patient and/or applicable payor are obligated to reimburse the Company for services rendered based on the patient’s insurance benefits. • Payment terms are a function of a patient’s existing insurance benefits, including the impact of coverage decisions with the Centers for Medicare & Medicaid Services, or CMS, and applicable reimbursement contracts established between the Company and payors, unless the patient is a self-pay patient, whereby the Company bills the patient directly after the services are provided. • Once the Company delivers a patient’s assay result to the ordering physician, the contract with a patient has commercial substance, as the Company is legally able to collect payment and bill an insurer and/or patient, regardless of payor contract status or patient insurance benefit status. • Consideration associated with commercial revenues is considered variable and constrained until fully adjudicated, with net revenues recorded to the extent that it is probable that a significant reversal will not occur. The Company’s development services revenues are supported by contractual agreements and generated from assay development services provided to entities, such as pharma or biotech organizations, as well as certain other diagnostic services provided to physicians, and revenues are recognized upon satisfaction of the performance obligations in the contract. Performance Obligations A performance obligation is a promise in a contract to transfer a distinct good or service, or a bundle of goods or services, to the customer. For its commercial and development services revenues, the Company’s contracts have a single performance obligation, which is satisfied upon rendering of services, which culminates in the delivery of a patient’s assay result(s) to the ordering physician or entity. The duration of time between accession receipt and delivery of a valid assay result to the ordering physician or entity is typically less than two weeks, and for our RT-PCR COVID-19 testing, was typically 48 hours or less. Accordingly, the Company elected the practical expedient and therefore, does not disclose the value of unsatisfied performance obligations. Transaction Price The transaction price is the amount of consideration that the Company expects to collect in exchange for transferring promised goods or services to a customer, excluding amounts collected on behalf of third parties, such as sales taxes. The consideration expected from a contract with a customer may include fixed amounts, variable amounts, or both. The Company’s gross commercial revenues billed, and corresponding gross accounts receivable, subject to price concessions to arrive at reported net revenues, which relate to differences between amounts billed and corresponding amounts estimated to be subsequently collected and is deemed to be variable although the variability is not explicitly stated in any contract. Rather, the variability is due to several factors, such as the payment history or lack thereof for third-party payors, reimbursement rate changes for contracted and non-contracted payors, any patient co-payments, deductibles or compliance incentives, the existence of secondary payors and claim denials. The Company estimates the amount of variable consideration using the most likely amount approach to estimating variable consideration for third-party payors, including direct patient bills, whereby the estimated reimbursement for services is established by payment histories on CPT codes for each payor, or similar payor types. When no payment history is available, the value of the account is estimated at Medicare rates, with additional other payor-specific reserves taken as appropriate. Collection periods for billings on commercial revenues range from less than 30 days to several months, depending on the contracted or non- contracted nature of the payor, among other variables. The estimates of amounts that will ultimately be realized from commercial diagnostic services for non-contracted payors require significant judgment by management. The Company limits the amount of variable consideration included in the transaction price to the unconstrained portion of such consideration. Revenue is recognized up to the amount of variable consideration that is not subject to a significant reversal until additional information is obtained or the uncertainty associated with the additional payments or refunds is subsequently resolved. Differences between original estimates and subsequent revisions, including final settlements, represent changes in the estimate of implicit price concessions and are included in the period in which such revisions are made. The Company monitors its estimates of transaction price to depict conditions that exist at each reporting date. If the Company subsequently determines that it will collect more consideration than it originally estimated for a contract with a customer, it will account for the change as an increase in the estimate of the transaction price in the period identified as an increase to revenue. Similarly, if the Company subsequently determines that the amount it expects to collect from a customer is less than it originally estimated, it will generally account for the change as a decrease in the estimate of the transaction price as a decrease to revenue. Allocate Transaction Price For the Company’s commercial revenues, the entire transaction price is allocated to the single performance obligation contained in a contract with a customer. For the Company’s development services revenues, the contracted transaction price is allocated to each single performance obligation contained in a contract with a customer as performed. Point-in-time Recognition The Company’s single performance obligation is satisfied at a point in time, and that point in time is defined as the date a patient’s successful assay result is delivered to the patient’s ordering physician or entity. The Company considers this date to be the time at which the patient obtains control of the promised diagnostic assay service. Contract Balances The timing of revenue recognition, billings and cash collections results in accounts receivable recorded in the Company’s balance sheets. Generally, billing occurs subsequent to delivery of a patient’s test result to the ordering physician or entity. Practical Expedients The Company does not adjust the transaction price for the effects of a significant financing component, as at contract inception, the Company expects the collection cycle to be one year or less. The Company expenses sales commissions when incurred because the amortization period is one year or less; such amounts are recorded within sales and marketing expenses. The Company incurs certain other costs that are incurred regardless of whether a contract is obtained. Such costs are primarily related to legal services and patient communications. These costs are expensed as incurred and recorded within general and administrative expenses. Disaggregation of Revenue and Concentration of Risk The composition of the Company’s net revenues recognized during the years ended December 31, 2022 and 2021, disaggregated by source and nature, are as follows (in thousands): For the year ended December 31, 2022 2021 Net revenues from non-contracted payors $ 17,612 $ 25,671 Net revenues from contracted payors* 8,004 35,260 Net commercial revenues 25,616 60,931 Development services revenues 240 147 Kits and Specimen Collection Tubes (SCTs) 2 171 Total net revenues $ 25,858 $ 61,249 * Includes Medicare and Medicare Advantage, as reimbursement amounts are fixed. At December 31, 2022 and 2021 , unbilled accounts receivable totaled approximately $ 0.8 million and $ 3.5 million, respectively. Concentration of Risk Financial instruments that potentially subject the Company to concentrations of credit risk consist principally of temporary cash investments. Concentrations of credit risk with respect to revenues are primarily limited to geographies to which the Company provides a significant volume of its services, and to specific third-party payors of the Company’s services such as Medicare, insurance companies, and other third-party payors. The Company’s client base consists of a large number of geographically dispersed clients diversified across various customer types. The Company's third-party payors that represent more than 10% of total net revenues in any period presented during the years ended December 31, 2022 and 2021 were as follows: For the year ended December 31, 2022 2021 Medicare and Medicare Advantage/CARES Act 36 % 56 % Blue Cross Blue Shield 16 % 17 % Kaiser Permanente 16 % 6 % The Company's third-party payors that represent more than 10% of total net accounts receivable as of December 31, 2022 and 2021 were as follows: For the year ended December 31, 2022 2021 Medicare and Medicare Advantage/CARES Act 5 % 31 % Blue Cross Blue Shield 23 % 19 % The Company operates in one reportable business segment and historically has derived most revenues only from within the United States. Certain components used in the Company’s current or planned products are currently sourced from one supplier , for which alternative suppliers exist but the Company has not validated the product(s) of such alternative supplier(s), and substitutes for these components may not be obtained easily or may require substantial design or manufacturing modifications. Cash The Company places its cash with reputable financial institutions that are insured by the Federal Deposit Insurance Corporation, or FDIC. At times, deposits held may exceed the amount of insurance provided by the FDIC. The Company has not experienced any losses in its cash and believes they are not exposed to any significant credit risk. Inventories Inventories are valued at the lower of cost (first-in, first-out) or net realizable value. The two primary components of inventory balances are raw materials and subassemblies. Subassemblies are in process raw materials used in our laboratory operations. The Company records adjustments to its inventory for estimated obsolescence or diminution in net realizable value equal to the difference between the cost of the inventory and the estimated net realizable value. At the point of loss recognition, a new cost basis for that inventory is established, and subsequent changes in facts and circumstances do not result in the restoration or increase in that newly established cost basis. In addition, the Company records a liability for firm, non-cancelable, and unconditional purchase commitments with contract manufacturers and suppliers for quantities in excess of the Company’s future demand forecasts consistent with its valuation of excess and obsolete inventory. Fixed Assets Fixed assets consist of machinery and equipment, furniture and fixtures, computer equipment and software, leasehold improvements, financed equipment and construction in-process. Fixed assets are stated at cost less accumulated depreciation and amortization. Additions, improvements, and major renewals are capitalized. Maintenance, repairs, and minor renewals are expensed as incurred. Depreciation and amortization are recorded using the straight-line method over the estimated useful lives of the assets, which range from three to seven years . Leasehold improvements are amortized over the life of the lease or the asset, whichever is shorter. Depreciation and amortization expense for the years ended December 31, 2022 and 2021 was approximately $ 1.7 million and $ 1.5 million , respectively. Upon sale or disposal of fixed assets, the accounts are relieved of the cost and the related accumulated depreciation or amortization with any gain or loss recorded to the statement of operations and comprehensive loss. Fixed assets are reviewed for impairment whenever changes in circumstances indicate that the carrying amount of an asset may not be recoverable. These computations utilize judgments and assumptions inherent in the estimates of future cash flows to determine recoverability of these assets. If the assumptions about these assets were to change as a result of events or circumstances, the Company may be required to record an impairment loss. No material impairment losses were recorded in 2022 and 2021 . Stock-based Compensation The Company measures and recognizes compensation expense for all stock-based awards made to employees and directors based on their grant date fair values. The Company estimates the fair value of stock option awards on the date of grant using the Black-Scholes option pricing model, while the fair value of restricted stock unit awards, or RSUs, is determined by the Company’s stock price on the date of grant. The value of the portion of the award that is ultimately expected to vest is recognized as expense over the requisite service periods using the straight-line method. In addition, forfeitures are recorded when incurred. The Company determines the fair value of the stock-based compensation awards granted as either the fair value of the consideration received, or the fair value of the equity instruments issued, whichever is more reliably measurable. Calculating the fair value of stock-based awards requires the input of highly subjective assumptions into the Black-Scholes valuation model. Stock-based compensation expense is calculated using the Company’s best estimates, which involves inherent uncertainties, and the application of management’s judgment. Significant estimates include the expected life of the stock option, stock price volatility and risk-free interest rate. Research and Development Research and development costs are expensed as incurred. The amounts expensed in the years ended December 31, 2022 and 2021 were approximately $ 6.2 million and $ 5.0 million , respectively, which includes salaries of research and development personnel. Income Taxes The Company provides for income taxes utilizing the liability method. Under the liability method, current income tax expense or benefit is the amount of income taxes expected to be payable or refundable for the current year. A deferred income tax asset or liability is computed for the expected future impact of differences between the financial reporting and tax bases of assets and liabilities and for the expected future tax benefit to be derived from tax credits. Tax rate changes are reflected in the computation of the income tax provision during the period such changes are enacted. Deferred tax assets are reduced by a valuation allowance when, in management’s opinion, it is more likely than not that some portion or all of the deferred tax assets will not be realized. The Company considers the scheduled reversal of deferred tax liabilities, projected future taxable income, and tax planning strategies in making this assessment. The Company’s valuation allowance is based on available evidence, including its current year operating loss, evaluation of positive and negative evidence with respect to certain specific deferred tax assets including evaluation sources of future taxable income to support the realization of the deferred tax assets. The Company has established a full valuation allowance on the deferred tax assets as of December 31, 2022 and 2021 , and therefore has not recognized any income tax benefit or expense in the periods presented for federal tax purposes. The Company did recognize income tax expense of $ 125,000 for the year ended December 31, 2021 for state tax purposes. That has been reversed as an income tax benefit for the year ended December 31, 2022. A tax benefit from uncertain tax positions may be recognized by the Company when it is more-likely-than-not that the position will be sustained upon examination, including resolutions of any related appeals or litigation processes, based on the technical merits of the position. Income tax positions must meet a more-likely-than-not recognition threshold to be recognized. The Company recognizes interest and/or penalties related to income tax matters in income tax expense. There is no accrual for interest or penalties for income taxes on the balance sheets at December 31, 2022 and 2021 , and the Company has no t recognized interest and/or penalties in the statements of operations and comprehensive loss for the years ended December 31, 2022 and 2021 . Recent Accounting Pronouncements In June 2016, the FASB issued ASU 2016-13, Financial Instruments- Credit Losses , which requires the measurement of expected credit losses for financial instruments carried at amortized cost, such as accounts receivable, held at the reporting date based on historical experience, current conditions and reasonable forecasts. The main objective of this standard is to provide financial statement users with more decision-useful information about the expected credit losses on financial instruments and other commitments to extend credit held by a reporting entity at each reporting period. In November 2018, the FASB issued ASU 2018-19, Codification Improvements to Topic 326, Financial Instruments- Credit Losses , which included an amendment of the effective date. The standard is effective for the Company for annual reporting periods beginning after December 15, 2022. The Company does not expect the adoption of this standard to have a significant impact on its financial statements. In September 2022, the FASB issued ASU 2022-04, Liabilities-Supplier Finance Programs , to enhance the transparency of supplier finance programs. The main objective of this standard requires a buyer in a supplier finance program to disclose sufficient information about the program to allow a user of financial statements to understand the program’s nature, activity during the period, changes from period to period, and potential magnitude. The standard is effective for the Company for annual reporting periods beginning after December 15, 2022, including interim periods within those fiscal years. The Company is currently evaluating the expected impact the adoption of this standard will have on its financial statements.

Sales of Equity Securities

Sales of Equity Securities	12 Months Ended
	Dec. 31, 2022
Equity [Abstract]
Sales of Equity Securities	4. Sales of Equity Securities As part of a warrant repricing and exchange transaction, in January 2020, the Company issued an aggregate of 692,725 new warrants in exchange for the exercise of certain warrants issued by the Company in February 2019 and March 2019 for an aggregate of 692,725 shares of common stock and received net proceeds of approximately $ 2.3 million. As a result of the warrant repricing, the exercise price of warrants to purchase an aggregate of 89,657 shares of common stock issued by the Company in January 2018 was adjusted from $ 4.05 to $ 3.495 per share. In January 2020, the Company issued 192,750 shares of common stock pursuant to the partial exercise of the underwriters’ overallotment option from the Company’s December 2019 public offering. The net proceeds to the Company from the overallotment closing was approximately $ 700,000 . The warrants issued in connection with the warrant repricing and exchange transaction were considered inducement warrants and are classified in equity. In addition, the modification expense associated with the change in fair value due to the repricing of February and March 2019 warrants is recorded as inducement expense, which was approximately $ 191,000 . The fair value of the warrants issued was approximately $ 1.9 million. The fair value of the inducement warrants and warrant modification of $ 2.1 million was expensed as warrant inducement expense in the accompanying statement of operations for the year ended December 31, 2021. On May 12, 2021, the Company entered into a Controlled Equity Offering SM Sales Agreement (the “Sales Agreement”) with Cantor Fitzgerald & Co. (the “Sales Agent”), under which the Company could issue and sell from time to time up to $ 25,000,000 of its common stock through or to the Sales Agent, as sales agent or principal. The issuance and sale of these shares under the Sales Agreement, if any, is subject to the continued effectiveness of a shelf registration statement on Form S-3 cover the sale of such shares. Our shelf registration statement on Form S-3, filed with the SEC on April 24, 2020, is no longer available and we will not be able to file a new Form S-3 until, at the earliest, September 1, 2023. Sales of the Company’s common stock, under the Sales Agreement are made at market prices by any method that is deemed to be an “at the market offering” as defined in Rule 415(a)(4) under the Securities Act of 1933, as amended. Each time the Company wishes to issue and sell common stock under the Sales Agreement, it notifies the Sales Agent of the number of shares to be issued, the dates on which such sales are anticipated to be made and any minimum price below which sales may not be made. Once the Company has so instructed the Sales Agent, unless the Sales Agent declines to accept the terms of the notice, the Sales Agent has agreed to use its commercially reasonable efforts consistent with its normal trading and sales practices to sell such shares up to the amount specified on such terms. The obligations of the Sales Agent under the Sales Agreement to sell the Company’s common stock are subject to a number of conditions that the Company must meet. The offering of common stock pursuant to the Sales Agreement will terminate upon the earlier of (1) the sale of all common stock subject to the Sales Agreement and (2) termination of the Sales Agreement as permitted therein. The Sales Agreement may be terminated by either party at any time upon ten days’ prior notice. The Sales Agent is entitled to compensation from the Company at a fixed commission rate equal to 3.0 % of the gross sales price per share of any common stock sold under the Sales Agreement. During 2022, the Company received net proceeds of $ 0.2 million from the sale of our common stock and issued 219,910 shares of our common stock at a weighted average purchase price of $ 1.29 . During 2021, the Company received net proceeds of $ 14.1 million from the sale of our common stock and issued 3,428,680 shares of our common stock at a weighted average purchase price of $ 4.31 pursuant to the Sales Agreement.

Payor Liability

Payor Liability	12 Months Ended
	Dec. 31, 2022
Payor Liability [Abstract]
Payor Liability	5. Payor Liability In March 2022, the U.S. Health Resources and Services Administration, or HRSA, informed providers that, after March 22, 2022, it would stop accepting claims for testing and treatment for uninsured individuals under the HRSA COVID-19 Uninsured Program and that claims submitted prior to that date would be subject to eligibility and availability of funds. HRSA’s procedure for recouping credits due from service providers had been to net these amounts against reimbursements for services provided. Given that no further payments are expected from HRSA, there is no longer a mechanism for recoupments. The Company has therefore recorded a liability for outstanding HRSA credits which were previously netted against accounts receivable.

Balance Sheet Details

Balance Sheet Details	12 Months Ended
	Dec. 31, 2022
Balance Sheet Component [Abstract]
Balance Sheet Details	6. Balance Sheet Details The following provides certain balance sheet details (in thousands): December 31, December 31, 2022 2021 Inventories Raw materials $ 1,564 $ 2,486 Subassemblies 401 324 Finished goods 36 42 2,001 $ 2,852 Less: inventory reserve ( 1,244 ) $ ( 201 ) Total inventories, net $ 757 $ 2,651 Fixed Assets Machinery and equipment $ 3,183 $ 3,063 Furniture and office equipment 160 161 Computer equipment and software 3,824 2,931 Leasehold improvements 689 634 Construction in process 39 245 $ 7,895 $ 7,034 Less accumulated depreciation and amortization ( 5,323 ) ( 4,633 ) Total fixed assets, net $ 2,572 $ 2,401 Accrued Liabilities Accrued payroll 605 725 Accrued vacation 799 961 Accrued bonuses 90 178 Accrued sales commissions 52 600 Accrued 401(k) match 220 283 Accrued other 483 271 Total accrued liabilities $ 2,249 $ 3,018

Leases

Leases	12 Months Ended
	Dec. 31, 2022
Leases [Abstract]
Leases	7. Leases Financed Leases The Company leases certain laboratory equipment under arrangements previously accounted for as capital leases, classified on the Company’s balance sheet as fixed assets and related lease liabilities, and depreciated on a straight-line basis over the lease term. The equipment under finance leases is depreciated on a straight-line basis over periods ranging from approximately 5 to 7 years. The total gross value of equipment capitalized under such lease arrangements was approximately $ 7.2 million and $ 6.0 million at December 31, 2022 and 2021, respectively. Total accumulated depreciation related to equipment under finance leases was approximately $ 4.1 million and $ 3.2 million at December 31, 2022 and 2021, respectively. Total depreciation expense related to equipment under finance leases was approximately $ 0.9 million during the years ended December 31, 2022 and 2021. During the year ended December 31, 2022, the Company entered into finance leases for a total capitalized amount of $ 1.1 million for three pieces of equipment. Under the terms of the financing agreements, the principal balance plus interest for the equipment are to be paid in installments of 36 to 60 monthly installments of approximately $ 20,000 totaling approximately $ 0.9 million through August 2027 . During the year ended December 31, 2021, the Company entered into finance leases for a total capitalized amount of $ 1.2 million for seven pieces of equipment. Under the terms of the financing agreements, the principal balance plus interest for the equipment are to be paid in installments ranging from 36 to 60 months totaling approximately $ 1.6 million through March 2026 . Operating Lease On June 1, 2020, the Company entered into a lease for a 39,000 square foot headquarters, manufacturing and laboratory facility at 9955 Mesa Rim Road in San Diego, California. The lease commenced on December 1, 2020 and is for a term of 127 months from the commencement date. The lease included a rent abatement period of seven months, from January 2021 through July of 2021, during which period the Company was exempt from paying the amount of base rent of $ 111,000 . In addition, the lease stipulated an additional two months of lease abatement period in the event that the property is sold within the first six months of the initial lease period. In March 2021, the Company was notified that the original landlord had sold the building, hence the Company was eligible for an additional two months of rent abatement period. In addition, the landlord agreed to pay for certain preapproved leasehold improvement costs through a one-time leasehold improvement allowance of approximately $ 1.6 million. The amount of additional leasehold improvement allowance of approximately $ 1.6 million is to be paid back to the landlord during the term of the lease by the Company, amortized at an agreed upon annual rate of 7 % as an additional rent payment of approximately $ 18,000 per month. The average monthly cash payment including payment for the additional leasehold improvement allowance for the lease is approximately $ 140,000 per month with initial monthly lease payments of $ 128,000 per month. The Company recorded a lease right-of-use asset and lease liability of $ 9.8 million as of December 31, 2020, based on the present value of payments and an incremental borrowing rate of 12 %. As the Company’s lease did not provide an implicit rate, the Company estimated the incremental borrowing rate based on the credit quality of the Company and by comparing interest rates available in the market for similar borrowings. The Company recorded $ 1.6 million in other current assets related to reimbursable leasehold improvement costs incurred as of December 31, 2020. The landlord reimbursed the Company $ 1.8 million during the year ended December 31, 2021. The following schedule represents the components of lease expense for the years ended December 31, 2022 and 2021 (in thousands): December 31, December 31, 2022 2021 Lease cost Finance lease cost Amortization of right-of-use assets $ 920 $ 863 Interest on lease liabilities 196 277 Operating lease cost 1,658 1,656 Total $ 2,774 $ 2,796 The following schedule represents maturities of operating and finance lease liabilities as of December 31, 2022 (in thousands): Finance Operating Minimum Minimum Lease Lease Payments Payments 2023 $ 1,200 $ 1,629 2024 770 1,672 2025 396 1,715 2026 192 1,762 2027 15 1,805 Thereafter - 6,713 Total payments 2,573 15,296 Less amount representing interest ( 274 ) ( 5,603 ) Present value of payments $ 2,299 $ 9,693 The following schedule sets forth supplemental cash flow information related to operating and finance leases as of December 31, 2022 and 2021 (in thousands): December 31, December 31, 2022 2021 Other information Operating cash flows from finance leases $ 196 $ 277 Operating cash flows from operating lease $ 1,586 $ 549 Financing cash flows from finance leases $ 1,305 $ 1,150 The aggregate weighted average remaining lease term was 2.55 years on finance leases and 8.50 years on operating leases as of December 31, 2022 . The aggregate weighted average discount rate was 9.07 % on finance leases and 12 % on the operating lease as of December 31, 2022 .

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2022
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation	8. Stock-Based Compensation Equity Incentive Plans The Company has two equity incentive plans: The Amended and Restated 2013 Equity Incentive Plan, or the 2013 Plan, and the 2007 Equity Incentive Plan, or the 2007 Plan. The 2013 Plan includes a provision that shares available for grant under the Company’s 2007 plan become available for issuance under the 2013 Plan and are no longer available for issuance under the 2007 Plan. At the Company’s annual meeting of stockholders held on July 16, 2021, the Company’s stockholders approved amendments to the 2013 Plan, which included an increase in the number of non-inducement shares of common stock authorized for issuance under the 2013 Plan by 1,300,000 shares. On February 14, 2022 and March 22, 2022, the board of directors approved an increase of 1,000,000 and 500,000 shares, respectively, in the inducement shares of common stock authorized for issuance under the 2013 Plan. Stock Options Non-performance options granted under either plan vest over a maximum period of four years and expire ten years from the date of grant. Non-performance options generally vest either (i) over four years, 25 % on the one-year anniversary of the date of grant and monthly thereafter for the remaining three years ; or (ii) over four years, monthly vesting beginning month-one after the grant and monthly thereafter . The fair value of stock options is determined on the date of grant using the Black-Scholes valuation model. For non-performance awards, such value is recognized as expense over the requisite service period using the straight-line method. The amount and timing of compensation expense recognized for performance awards is based on management’s estimate of the most likely outcome and when the achievement of the performance objectives is probable. The determination of the fair value of stock options is affected by the Company’s stock price, as well as assumptions regarding a number of complex and subjective variables. The volatility assumption is based on the historical volatility of the Company’s common stock over a period of time equal to the expected term of the stock options. The expected term of employee stock options represents the weighted-average period the stock options are expected to remain outstanding. The expected term assumption is estimated based primarily on the options’ vesting terms and remaining contractual life and employees’ expected exercise and post-vesting employment termination behavior. The risk-free interest rate assumption is based upon observed interest rates on the grant date appropriate for the term of the employee stock options. The dividend yield assumption is based on the expectation of no future dividend payouts by the Company. The assumptions used in the Black-Scholes pricing model for options granted during the years ended December 31, 2022 and 2021 are as follows: 2022 2021 Stock and exercise prices $ 0.74 - $ 2.39 $ 3.62 - $ 6.03 Expected dividend yield 0.00 % 0.00 % Discount rate-bond equivalent yield 0.51 % - 4.36 % 0.52 % - 1.15 % Expected life (in years) 5.50 - 6.03 5.0 - 5.98 Expected volatility 160 % - 180 % 163.1 % - 173.9 % A summary of stock option activity for the years ended December 31, 2022 and 2021 is as follows: Number of Weighted Weighted Outstanding at December 31, 2020 1,078,704 $ 11.64 9.36 Granted 1,558,510 $ 3.96 Exercised ( 537 ) 3.14 Cancelled/forfeited/expired ( 256,681 ) $ 7.83 Outstanding at December 31, 2021 2,379,996 $ 7.07 9.06 Granted 1,412,900 $ 2.10 Cancelled/forfeited/expired ( 1,529,495 ) $ 7.28 Outstanding at December 31, 2022 2,263,401 $ 3.85 8.86 Vested and unvested expected to vest, December 31, 2022 2,236,680 $ 3.89 8.81 The intrinsic values of options outstanding, options exercisable, and options vested and unvested expected to vest at December 31, 2022 and 2021 were $ 0 and $ 610 , respectively. Stock-based Compensation Expense The following table presents the effects of stock-based compensation related to equity awards to employees and nonemployees on the statement of operations during the periods presented (in thousands): Years Ended December 31, 2022 2021 Stock Options Cost of revenues $ 628 $ 598 Research and development expenses 300 231 General and administrative expenses 1,860 1,266 Sales and marketing expenses 439 367 Total stock-based compensation $ 3,227 $ 2,462 As of December 31, 2022 , total unrecognized share-based compensation expense related to unvested stock options was approximately $ 3.7 million and such amount is expected to be recognized over a weighted-average period of approximately 2.46 years.

Common Stock Warrants Outstandi

Common Stock Warrants Outstanding	12 Months Ended
	Dec. 31, 2022
Equity Classified Warrants [Abstract]
Common Stock Warrants Outstanding	9. Common Stock Warrants Outstanding A summary of equity-classified common stock warrant activity, for warrants other than those underlying unexercised overallotment option warrants, during 2022 and 2021 is as follows: Average Weighted Remaining Number of Average Exercise Contractual Shares Price Per Share Term in Years Outstanding at December 31, 2020 997,167 $ 35.48 3.3 Issued — $ — Exercised ( 126,330 ) $ 3.52 Expired ( 13,576 ) $ 569.89 Outstanding at December 31, 2021 857,261 $ 31.73 2.2 Issued — $ — Exercised — $ — Expired ( 12,801 ) $ 606.22 Outstanding at December 31, 2022 844,460 $ 23.02 1.3 All warrants outstanding at December 31, 2022 and 2021 are exercisable. Warrants issued in the February 2019 financing transaction have an expiration date of February 12, 2024 , warrants issued in the March 2019 transaction have an expiration date of September 19, 2024 , warrants issued in the May 2019 inducement offering have an expiration date of December 2, 2024 , warrants issued in the December 2019 have an expiration date of December 11, 2024 , and warrants issued in the January 2020 inducement offering have an expiration date of July 10, 2025 . The intrinsic value of equity-classified common stock warrants outstanding at December 31, 2022 and 2021 was $ 0 and $ 16,000 , respectively.

Net Loss per Common Share

Net Loss per Common Share	12 Months Ended
	Dec. 31, 2022
Earnings Per Share [Abstract]
Net Loss per Common Share	10. Net Loss per Common Share Basic and diluted net loss per common share is determined by dividing net loss applicable to common shareholders by the weighted-average common shares outstanding during the period. Because there is a net loss attributable to common shareholders for the years ended December 31, 2022 and 2021, the outstanding RSUs, warrants, and common stock options have been excluded from the calculation of diluted loss per common share because their effect would be anti-dilutive. Therefore, the weighted-average shares used to calculate both basic and diluted loss per share are the same. The following potentially dilutive securities have been excluded from the computations of diluted weighted-average shares outstanding for the periods presented, as they would be anti-dilutive: December 31, December 31, 2022 2021 Common warrants outstanding 844,460 857,261 RSUs outstanding - 36 Convertible preferred stock outstanding (number of common stock equivalents) 46,541 46,541 Common options outstanding 2,263,401 2,379,996 Total anti-dilutive common share equivalents 3,154,402 3,283,834

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Income Taxes	11. Income Taxes For the years ended December 31, 2022 and 2021, the provision for income taxes was calculated as follows (in thousands): December 31, December 31, 2022 2021 Current: Federal $ — $ — State ( 125 ) 125 Total ( 125 ) 125 Deferred Federal — — State — — Total — — Provision for income tax $ ( 125 ) $ 125 The following table reconciles income taxes computed at the federal statutory rate and the Company’s provision for income taxes (in thousands): December 31, December 31, 2022 2021 Income tax at statutory rate $ ( 6,766 ) $ ( 567 ) Change in federal tax rate — State liability ( 1,694 ) 66 Permanent items 210 278 Stock compensation 960 178 Warrant inducement — — Expiration of net operating losses 710 594 Research and development credit ( 178 ) ( 377 ) Unrecognized tax benefits 125 2,956 State rate change 76 ( 480 ) Estimated section 382 limitation ( 358 ) ( 485 ) Return to provision ( 132 ) ( 8 ) Other 131 28 Valuation allowance 6,791 ( 2,058 ) Provision for income tax $ ( 125 ) $ 125 Deferred income taxes are provided for temporary differences in recognizing certain income and expense items for financial and tax reporting purposes. The deferred tax assets consisted primarily of the income tax benefits from accruals, estimated net operating loss carryforwards, and estimated research and development credits. Valuation allowances have been recorded to fully offset deferred tax assets at December 31, 2022 and 2021, as it is more likely than not that the assets will not be utilized. At December 31, 2022 , the Company had estimated federal net operating loss carryforwards of approximately $ 91.3 million with $ 80.7 million net operating losses generated in tax years beginning after December 31, 2017 carrying forward indefinitely and may generally be used to offset up to 80 % of future taxable income. Additionally, the remaining estimated net operating loss carryforwards of approximately $ 10.6 million will begin to expire in 2023 . The Company has additional state net operating losses of $ 66.8 million with $ 3.6 million net operating losses generated after December 31, 2017, carrying forward indefinitely and may generally be used to offset up to 80 % of future taxable income. Additionally, the remaining estimated net operating loss carryforwards of approximately $ 63.2 million will begin to expire in 2027 . Additionally, at December 31, 2022 , the Company had estimated research and development tax credits of approximately $ 1.0 million and $ 4.0 million for federal and California purposes, respectively. The federal research and development tax credits will begin to expire in 2023 . The California research and development tax credits do not expire. For the years ended December 31, 2022 and 2021 , the Company has evaluated the various tax positions reflected in its income tax returns for both federal and state jurisdictions, to determine if the Company has any uncertain tax positions on the historical tax returns. The Company recognizes the impact of an uncertain tax position on an income tax return at the largest amount that the relevant taxing authority is more-likely-than not to sustain upon audit. The Company does not recognize uncertain income tax positions if they have less than 50 % likelihood of being sustained. Based on this assessment, the Company believes there are tax positions for which a liability for unrecognized tax benefits should be recorded as of December 31, 2022 and 2021 . The following table summarizes the activity related to our gross unrecognized tax benefits (in thousands): December 31, December 31, 2022 2021 Current: Balance at the beginning of the year $ 3,679 $ — Adjustments related to prior year tax positions 25 3,640 Increases related to current year tax positions 118 39 Decreases for tax positions from prior years — — Provision for income tax $ 3,822 $ 3,679 The Company is subject to U.S. federal income tax as well as income tax in multiple state jurisdictions. With few exceptions, the Company is no longer subject to U.S. federal income tax examinations for tax years ending on or before December 31, 2018, and state and local income tax examinations for tax periods ending on or before December 31, 2001. However, to the extent allowed by law, the tax authorities may have the right to examine prior periods where net operating losses were generated and carried forward and make adjustments up to the amount of the net operating loss carryforward amount. The Company’s policy is to recognize interest and penalties related to income tax matters in income tax expense. Due to the existence of the valuation allowance, future changes in unrecognized tax benefits will not impact the Company’s effective tax rate. The Company is currently not under examination by any taxing authorities and does not believe its unrecognized tax benefits will significantly change in the next twelve months. The tax effects of carryforwards and other temporary differences that give rise to deferred tax assets consist of the following (in thousands): For the year ended December 31, 2022 2021 Estimated net operating loss carryforward $ 23,598 $ 18,482 Estimated research and development credits 1,032 1,026 Capitalized research and development 1,490 470 Accruals and other 3,234 2,046 Operating lease liability 2,648 2,821 Fixed assets 417 368 Stock based compensation 617 1,164 33,036 26,377 Right-of-use asset ( 3,161 ) ( 3,295 ) Gross deferred tax liabilities ( 3,161 ) ( 3,295 ) Less valuation allowance ( 29,875 ) ( 23,082 ) Net deferred tax assets $ — $ — Utilization of the estimated domestic net operating loss and research and development tax credit carryforwards may be subject to a substantial annual limitation due to ownership change limitations that may have occurred or that could occur in the future, as required by Sections 382 and 383 of the Code, as well as similar state provisions. These ownership changes may limit the amount of estimated net operating loss and research and development credit carryforwards that can be utilized annually to offset future taxable income and tax, respectively. In general, an “ownership change” as defined by Section 382 of the Code results from a transaction or series of transactions over a three-year period resulting in an ownership change of more than 50 percentage points by value of the outstanding stock of a company by certain stockholders. Since the Company’s formation, the Company has raised capital through the issuance of capital stock on several occasions which on its own or combined with the purchasing stockholders’ subsequent disposition of those shares, likely resulted in such an ownership change, or could result in an ownership change in the future. Upon the occurrence of an ownership change under Sections 382 and 383 of the Code as outlined above, utilization of the estimated net operating loss and research and development credit carryforwards are subject to an annual limitation, which is determined by first multiplying the value of the Company’s stock at the time of the ownership change by the applicable long-term, tax-exempt rate, which could be subject to additional adjustments, as required. Any limitation may result in expiration of a portion of the estimated net operating loss or research and development tax credit carryforwards before utilization. The Company has not yet completed an analysis to determine whether an ownership change has occurred, however, the Company believes multiple ownership changes have likely occurred. As a result, the Company has estimated that the use of its net operating loss carryforwards is limited and has disclosed in the table above only the amounts it estimates could be used in the future, which remain fully offset by a valuation allowance to reduce the net asset to zero. The Tax Cuts and Jobs Act (TCJA) requires tax payors to capitalize and amortize research and development (R&D) expenditures under section 174 for tax years beginning after December 31, 2021. This rule became effective for the Company during the year and resulted in the capitalization of R&D costs of approximately $ 5.2 million. The Company will amortize these costs for tax purposes over 5 years if the R&D was performed in the U.S. and over 15 years if the R&D was performed outside the U.S.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2022
Related Party Transactions [Abstract]
Related Party Transactions	12. Related Party Transactions A former member of the Company’s management is the controlling person of Aegea Biotechnologies, Inc., or Aegea. On September 2, 2012, the Company entered into an Assignment and Exclusive Cross-License Agreement, or the Cross-License Agreement, with Aegea. The Company received payments totaling approximately $ 0 and $ 49,000 during the years ended December 31, 2022 and 2021, respectively, from Aegea as reimbursements for shared patent costs under the Cross-License Agreement. On December 11, 2019, the Company entered into a First Amendment to Assignment and Exclusive Cross-License Agreement with Aegea pursuant to which the Company obtained a royalty bearing license for a certain patent. On May 22, 2022, the Company entered into a Second Amendment to Assignment and Exclusive Cross-License Agreement with Aegea pursuant to which the Company obtained a royalty-free license for a certain patent and Aegea obtained certain patents.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	13. Commitments and Contingencies In the normal course of business, the Company may be involved in legal proceedings or threatened legal proceedings. The Company is not party to any legal proceedings or aware of any threatened legal proceedings except as provided in the paragraph below, and except for those proceedings that are not expected to have a material adverse effect on the Company’s financial condition, results of operations or liquidity. The Company was in mediation with former employees regarding disputed claims for certain sales commissions. Although the Company was not in agreement with their interpretations or claims, the Company entered into settlement negotiations related to the disputed commissions. The matter was resolved in June 2022 for approximately $ 1.7 million and was recorded within sales and marketing expense.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2022
Subsequent Events [Abstract]
Subsequent Events	14. Subsequent Events From January 1, 2023 through the issuance of the financial statements, the Company sold and issued 707,114 shares of our common stock at a weighted average purchase price of $ 0.57 under the Company’s at-the-market equity facility, for net proceeds of $ 0.4 million. On January 6, 2023, the Company announced that it had commenced a process to explore and evaluate strategic alternatives to enhance shareholder value, and that in connection with such process and in order to extend the Company's resources, the Company has implemented a restructuring plan that resulted in a reduction of the Company's workforce by approximately 36 %. The Company has incurred charges of approximately $ 0.8 million for severance and other employee termination-related costs in the first quarter of 2023. The Company may also incur additional costs not currently contemplated due to events that may occur as a result of, or that are associated with its workforce reduction. On March 16, 2023, the Company terminated the employment of Michael C. Dugan, M.D., the Company’s Senior Vice President, Chief Medical Officer and Medical Director, effective March 17, 2023. In connection with his termination, the Company entered into a separation agreement, in exchange for a release of claims, and agreed to provide severance benefits of approximately $ 0.1 million, to be made during the year ending December 31, 2023.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2022
Summary Of Significant Accounting Policies [Line Items]
The Company and Business Activities	The Company and Business Activities Biocept, Inc., the Company, was founded in California in May 1997 and is a molecular oncology diagnostics company that develops and commercializes proprietary circulating tumor cell and circulating cell-free tumor DNA and RNA assays utilizing a standard blood sample, or liquid biopsy. The Company’s current and planned assays are intended to provide information to aid healthcare providers to identify specific oncogenic alterations that may qualify a subset of cancer patients for targeted therapy at diagnosis, progression or for monitoring to identify specific resistance mechanisms. Sometimes traditional procedures, such as surgical tissue biopsies, result in tumor tissue that is insufficient and/or unable to provide the molecular subtype information necessary for clinical decisions. The Company’s assays, performed on blood and cerebral spinal fluid, have the potential to provide more contemporaneous information on the characteristics of a patient’s disease when compared with tissue biopsy and radiographic imaging. Further, sales to laboratory supply distributors of the Company’s proprietary SCTs commenced in June 2018, which allow for the intact transport of liquid biopsy samples for research use only, or RUO, from regions around the world. The Company operates a clinical laboratory that is CLIA-certified (under the Clinical Laboratory Improvement Amendment of 1988) and CAP-accredited (by the College of American Pathologists), and manufactures cell enrichment and extraction microfluidic channels, related equipment and certain reagents to perform the Company’s diagnostic assays in a facility located in San Diego, California. CLIA certification and accreditation are required before any clinical laboratory may perform testing on human specimens for the purpose of obtaining information for the diagnosis, prevention, treatment of disease, or assessment of health. The assays the Company offers are classified as laboratory developed tests under the CLIA regulations. In July 2013, the Company effected a reincorporation to Delaware by merging itself with and into Biocept, Inc., a Delaware corporation, which had been formed to be and was a wholly-owned subsidiary of the Company since July 23, 2013. The Company experienced increased revenue levels in 2022 and 2021 related to its COVID-19 testing business. I n February, 2023, due to reduced demand, the Company ceased COVID-19 testing services.
Basis of Presentation	Basis of Presentation The accompanying financial statements and notes are prepared in accordance with accounting principles generally accepted in the United States of America, or U.S. GAAP, and are prepared on the basis that the Company will continue as a going concern (see Note 2). The accompanying financial statements and notes do not include any adjustments to reflect the possible future effects on the recoverability and classification of assets or the amounts and classification of liabilities that may result from the possible inability of the Company to continue as a going concern.
Reclassification	Reclassification The Company reclassified the change in inventory reserve for the year ended December 31, 2021 of approximately $ 0.1 million within the statement of cash flows to conform to the current year presentation. The change in inventory reserve is now included in the increase (decrease) in cash resulting from changes in inventory within the cash flows from operating activities. This reclassification had no effect on previously reported cash flows from operating activities in the statement of cash flows.
Going Concern	Going Concern The Company assesses and determines its ability to continue as a going concern in accordance with the provisions of ASC Topic 205-40, Presentation of Financial Statements—Going Concern, which requires the Company to evaluate whether there are conditions or events that raise substantial doubt about its ability to continue as a going concern within one year after the date that its annual and interim financial statements are issued (see Note 2). Certain additional financial statement disclosures are required if such conditions or events are identified. If and when an entity’s liquidation becomes imminent, financial statements should be prepared under the liquidation basis of accounting. Determining the extent, if any, to which conditions or events raise substantial doubt about the Company’s ability to continue as a going concern, or the extent to which mitigating plans sufficiently alleviate any such substantial doubt, as well as whether or not liquidation is imminent, requires significant judgment by management.
Use of Estimates	Use of Estimates The preparation of financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. On an ongoing basis, management evaluates these estimates and judgments, including those related to accounts receivable reserves, inventory reserves, long-lived asset impairment and useful lives, income taxes, including uncertain tax benefits, estimated transaction price for revenues, stock-based compensation, incremental borrowing rate estimates, and the determination of the Company’s ability to continue as a going concern. The Company bases its estimates on various assumptions that it believes are reasonable under the circumstances. Actual results may differ from these estimates under different assumptions or conditions.
Revenue Recognition and Accounts Receivable	Revenue Recognition and Accounts Receivable The Company's commercial revenues are generated from diagnostic services provided to patient’s physicians and billed to third-party insurance payors such as managed care organizations, Medicare and Medicaid and patients for any deductibles, coinsurance or copayments that may be due. The Company recognizes revenue in accordance with ASC 606, Revenue from Contracts with Customers, which requires that an entity recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled to in exchange for those goods or services. Contracts For its commercial revenues, while the Company markets directly to physicians and other healthcare providers, the Company provides services that benefit the patient. Patients do not typically enter into direct agreements with the Company; however, a patient’s insurance coverage requirements would dictate whether or not any portion of the cost of the tests would be patient responsibility. Accordingly, the Company establishes contracts with commercial insurers in accordance with customary business practices, as follows: • Approval of a contract is established via the order and accession, which are submitted by the patient’s physician. • The Company is obligated to perform its diagnostic services upon receipt of a sample from a physician, and the patient and/or applicable payor are obligated to reimburse the Company for services rendered based on the patient’s insurance benefits. • Payment terms are a function of a patient’s existing insurance benefits, including the impact of coverage decisions with the Centers for Medicare & Medicaid Services, or CMS, and applicable reimbursement contracts established between the Company and payors, unless the patient is a self-pay patient, whereby the Company bills the patient directly after the services are provided. • Once the Company delivers a patient’s assay result to the ordering physician, the contract with a patient has commercial substance, as the Company is legally able to collect payment and bill an insurer and/or patient, regardless of payor contract status or patient insurance benefit status. • Consideration associated with commercial revenues is considered variable and constrained until fully adjudicated, with net revenues recorded to the extent that it is probable that a significant reversal will not occur. The Company’s development services revenues are supported by contractual agreements and generated from assay development services provided to entities, such as pharma or biotech organizations, as well as certain other diagnostic services provided to physicians, and revenues are recognized upon satisfaction of the performance obligations in the contract. Performance Obligations A performance obligation is a promise in a contract to transfer a distinct good or service, or a bundle of goods or services, to the customer. For its commercial and development services revenues, the Company’s contracts have a single performance obligation, which is satisfied upon rendering of services, which culminates in the delivery of a patient’s assay result(s) to the ordering physician or entity. The duration of time between accession receipt and delivery of a valid assay result to the ordering physician or entity is typically less than two weeks, and for our RT-PCR COVID-19 testing, was typically 48 hours or less. Accordingly, the Company elected the practical expedient and therefore, does not disclose the value of unsatisfied performance obligations. Transaction Price The transaction price is the amount of consideration that the Company expects to collect in exchange for transferring promised goods or services to a customer, excluding amounts collected on behalf of third parties, such as sales taxes. The consideration expected from a contract with a customer may include fixed amounts, variable amounts, or both. The Company’s gross commercial revenues billed, and corresponding gross accounts receivable, subject to price concessions to arrive at reported net revenues, which relate to differences between amounts billed and corresponding amounts estimated to be subsequently collected and is deemed to be variable although the variability is not explicitly stated in any contract. Rather, the variability is due to several factors, such as the payment history or lack thereof for third-party payors, reimbursement rate changes for contracted and non-contracted payors, any patient co-payments, deductibles or compliance incentives, the existence of secondary payors and claim denials. The Company estimates the amount of variable consideration using the most likely amount approach to estimating variable consideration for third-party payors, including direct patient bills, whereby the estimated reimbursement for services is established by payment histories on CPT codes for each payor, or similar payor types. When no payment history is available, the value of the account is estimated at Medicare rates, with additional other payor-specific reserves taken as appropriate. Collection periods for billings on commercial revenues range from less than 30 days to several months, depending on the contracted or non- contracted nature of the payor, among other variables. The estimates of amounts that will ultimately be realized from commercial diagnostic services for non-contracted payors require significant judgment by management. The Company limits the amount of variable consideration included in the transaction price to the unconstrained portion of such consideration. Revenue is recognized up to the amount of variable consideration that is not subject to a significant reversal until additional information is obtained or the uncertainty associated with the additional payments or refunds is subsequently resolved. Differences between original estimates and subsequent revisions, including final settlements, represent changes in the estimate of implicit price concessions and are included in the period in which such revisions are made. The Company monitors its estimates of transaction price to depict conditions that exist at each reporting date. If the Company subsequently determines that it will collect more consideration than it originally estimated for a contract with a customer, it will account for the change as an increase in the estimate of the transaction price in the period identified as an increase to revenue. Similarly, if the Company subsequently determines that the amount it expects to collect from a customer is less than it originally estimated, it will generally account for the change as a decrease in the estimate of the transaction price as a decrease to revenue. Allocate Transaction Price For the Company’s commercial revenues, the entire transaction price is allocated to the single performance obligation contained in a contract with a customer. For the Company’s development services revenues, the contracted transaction price is allocated to each single performance obligation contained in a contract with a customer as performed. Point-in-time Recognition The Company’s single performance obligation is satisfied at a point in time, and that point in time is defined as the date a patient’s successful assay result is delivered to the patient’s ordering physician or entity. The Company considers this date to be the time at which the patient obtains control of the promised diagnostic assay service. Contract Balances The timing of revenue recognition, billings and cash collections results in accounts receivable recorded in the Company’s balance sheets. Generally, billing occurs subsequent to delivery of a patient’s test result to the ordering physician or entity. Practical Expedients The Company does not adjust the transaction price for the effects of a significant financing component, as at contract inception, the Company expects the collection cycle to be one year or less. The Company expenses sales commissions when incurred because the amortization period is one year or less; such amounts are recorded within sales and marketing expenses. The Company incurs certain other costs that are incurred regardless of whether a contract is obtained. Such costs are primarily related to legal services and patient communications. These costs are expensed as incurred and recorded within general and administrative expenses. Disaggregation of Revenue and Concentration of Risk The composition of the Company’s net revenues recognized during the years ended December 31, 2022 and 2021, disaggregated by source and nature, are as follows (in thousands): For the year ended December 31, 2022 2021 Net revenues from non-contracted payors $ 17,612 $ 25,671 Net revenues from contracted payors* 8,004 35,260 Net commercial revenues 25,616 60,931 Development services revenues 240 147 Kits and Specimen Collection Tubes (SCTs) 2 171 Total net revenues $ 25,858 $ 61,249 * Includes Medicare and Medicare Advantage, as reimbursement amounts are fixed. At December 31, 2022 and 2021 , unbilled accounts receivable totaled approximately $ 0.8 million and $ 3.5 million, respectively.
Concentration of Risk	Concentration of Risk Financial instruments that potentially subject the Company to concentrations of credit risk consist principally of temporary cash investments. Concentrations of credit risk with respect to revenues are primarily limited to geographies to which the Company provides a significant volume of its services, and to specific third-party payors of the Company’s services such as Medicare, insurance companies, and other third-party payors. The Company’s client base consists of a large number of geographically dispersed clients diversified across various customer types. The Company's third-party payors that represent more than 10% of total net revenues in any period presented during the years ended December 31, 2022 and 2021 were as follows: For the year ended December 31, 2022 2021 Medicare and Medicare Advantage/CARES Act 36 % 56 % Blue Cross Blue Shield 16 % 17 % Kaiser Permanente 16 % 6 % The Company's third-party payors that represent more than 10% of total net accounts receivable as of December 31, 2022 and 2021 were as follows: For the year ended December 31, 2022 2021 Medicare and Medicare Advantage/CARES Act 5 % 31 % Blue Cross Blue Shield 23 % 19 % The Company operates in one reportable business segment and historically has derived most revenues only from within the United States. Certain components used in the Company’s current or planned products are currently sourced from one supplier , for which alternative suppliers exist but the Company has not validated the product(s) of such alternative supplier(s), and substitutes for these components may not be obtained easily or may require substantial design or manufacturing modifications.
Cash	Cash The Company places its cash with reputable financial institutions that are insured by the Federal Deposit Insurance Corporation, or FDIC. At times, deposits held may exceed the amount of insurance provided by the FDIC. The Company has not experienced any losses in its cash and believes they are not exposed to any significant credit risk.
Inventories	Inventories Inventories are valued at the lower of cost (first-in, first-out) or net realizable value. The two primary components of inventory balances are raw materials and subassemblies. Subassemblies are in process raw materials used in our laboratory operations. The Company records adjustments to its inventory for estimated obsolescence or diminution in net realizable value equal to the difference between the cost of the inventory and the estimated net realizable value. At the point of loss recognition, a new cost basis for that inventory is established, and subsequent changes in facts and circumstances do not result in the restoration or increase in that newly established cost basis. In addition, the Company records a liability for firm, non-cancelable, and unconditional purchase commitments with contract manufacturers and suppliers for quantities in excess of the Company’s future demand forecasts consistent with its valuation of excess and obsolete inventory.
Fixed Assets	Fixed Assets Fixed assets consist of machinery and equipment, furniture and fixtures, computer equipment and software, leasehold improvements, financed equipment and construction in-process. Fixed assets are stated at cost less accumulated depreciation and amortization. Additions, improvements, and major renewals are capitalized. Maintenance, repairs, and minor renewals are expensed as incurred. Depreciation and amortization are recorded using the straight-line method over the estimated useful lives of the assets, which range from three to seven years . Leasehold improvements are amortized over the life of the lease or the asset, whichever is shorter. Depreciation and amortization expense for the years ended December 31, 2022 and 2021 was approximately $ 1.7 million and $ 1.5 million , respectively. Upon sale or disposal of fixed assets, the accounts are relieved of the cost and the related accumulated depreciation or amortization with any gain or loss recorded to the statement of operations and comprehensive loss. Fixed assets are reviewed for impairment whenever changes in circumstances indicate that the carrying amount of an asset may not be recoverable. These computations utilize judgments and assumptions inherent in the estimates of future cash flows to determine recoverability of these assets. If the assumptions about these assets were to change as a result of events or circumstances, the Company may be required to record an impairment loss. No material impairment losses were recorded in 2022 and 2021 .
Stock-based Compensation	Stock-based Compensation The Company measures and recognizes compensation expense for all stock-based awards made to employees and directors based on their grant date fair values. The Company estimates the fair value of stock option awards on the date of grant using the Black-Scholes option pricing model, while the fair value of restricted stock unit awards, or RSUs, is determined by the Company’s stock price on the date of grant. The value of the portion of the award that is ultimately expected to vest is recognized as expense over the requisite service periods using the straight-line method. In addition, forfeitures are recorded when incurred. The Company determines the fair value of the stock-based compensation awards granted as either the fair value of the consideration received, or the fair value of the equity instruments issued, whichever is more reliably measurable. Calculating the fair value of stock-based awards requires the input of highly subjective assumptions into the Black-Scholes valuation model. Stock-based compensation expense is calculated using the Company’s best estimates, which involves inherent uncertainties, and the application of management’s judgment. Significant estimates include the expected life of the stock option, stock price volatility and risk-free interest rate.
Research and Development	Research and Development Research and development costs are expensed as incurred. The amounts expensed in the years ended December 31, 2022 and 2021 were approximately $ 6.2 million and $ 5.0 million , respectively, which includes salaries of research and development personnel.
Income Taxes	Income Taxes The Company provides for income taxes utilizing the liability method. Under the liability method, current income tax expense or benefit is the amount of income taxes expected to be payable or refundable for the current year. A deferred income tax asset or liability is computed for the expected future impact of differences between the financial reporting and tax bases of assets and liabilities and for the expected future tax benefit to be derived from tax credits. Tax rate changes are reflected in the computation of the income tax provision during the period such changes are enacted. Deferred tax assets are reduced by a valuation allowance when, in management’s opinion, it is more likely than not that some portion or all of the deferred tax assets will not be realized. The Company considers the scheduled reversal of deferred tax liabilities, projected future taxable income, and tax planning strategies in making this assessment. The Company’s valuation allowance is based on available evidence, including its current year operating loss, evaluation of positive and negative evidence with respect to certain specific deferred tax assets including evaluation sources of future taxable income to support the realization of the deferred tax assets. The Company has established a full valuation allowance on the deferred tax assets as of December 31, 2022 and 2021 , and therefore has not recognized any income tax benefit or expense in the periods presented for federal tax purposes. The Company did recognize income tax expense of $ 125,000 for the year ended December 31, 2021 for state tax purposes. That has been reversed as an income tax benefit for the year ended December 31, 2022. A tax benefit from uncertain tax positions may be recognized by the Company when it is more-likely-than-not that the position will be sustained upon examination, including resolutions of any related appeals or litigation processes, based on the technical merits of the position. Income tax positions must meet a more-likely-than-not recognition threshold to be recognized. The Company recognizes interest and/or penalties related to income tax matters in income tax expense. There is no accrual for interest or penalties for income taxes on the balance sheets at December 31, 2022 and 2021 , and the Company has no t recognized interest and/or penalties in the statements of operations and comprehensive loss for the years ended December 31, 2022 and 2021 .
Recent Accounting Pronouncements	Recent Accounting Pronouncements In June 2016, the FASB issued ASU 2016-13, Financial Instruments- Credit Losses , which requires the measurement of expected credit losses for financial instruments carried at amortized cost, such as accounts receivable, held at the reporting date based on historical experience, current conditions and reasonable forecasts. The main objective of this standard is to provide financial statement users with more decision-useful information about the expected credit losses on financial instruments and other commitments to extend credit held by a reporting entity at each reporting period. In November 2018, the FASB issued ASU 2018-19, Codification Improvements to Topic 326, Financial Instruments- Credit Losses , which included an amendment of the effective date. The standard is effective for the Company for annual reporting periods beginning after December 15, 2022. The Company does not expect the adoption of this standard to have a significant impact on its financial statements. In September 2022, the FASB issued ASU 2022-04, Liabilities-Supplier Finance Programs , to enhance the transparency of supplier finance programs. The main objective of this standard requires a buyer in a supplier finance program to disclose sufficient information about the program to allow a user of financial statements to understand the program’s nature, activity during the period, changes from period to period, and potential magnitude. The standard is effective for the Company for annual reporting periods beginning after December 15, 2022, including interim periods within those fiscal years. The Company is currently evaluating the expected impact the adoption of this standard will have on its financial statements.
Stock Options [Member]
Summary Of Significant Accounting Policies [Line Items]
Fair Value Measurements	The fair value of stock options is determined on the date of grant using the Black-Scholes valuation model. For non-performance awards, such value is recognized as expense over the requisite service period using the straight-line method. The amount and timing of compensation expense recognized for performance awards is based on management’s estimate of the most likely outcome and when the achievement of the performance objectives is probable. The determination of the fair value of stock options is affected by the Company’s stock price, as well as assumptions regarding a number of complex and subjective variables. The volatility assumption is based on the historical volatility of the Company’s common stock over a period of time equal to the expected term of the stock options. The expected term of employee stock options represents the weighted-average period the stock options are expected to remain outstanding. The expected term assumption is estimated based primarily on the options’ vesting terms and remaining contractual life and employees’ expected exercise and post-vesting employment termination behavior. The risk-free interest rate assumption is based upon observed interest rates on the grant date appropriate for the term of the employee stock options. The dividend yield assumption is based on the expectation of no future dividend payouts by the Company.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
Composition of Net Revenues Recognized Disaggregated by Source and Nature	The composition of the Company’s net revenues recognized during the years ended December 31, 2022 and 2021, disaggregated by source and nature, are as follows (in thousands): For the year ended December 31, 2022 2021 Net revenues from non-contracted payors $ 17,612 $ 25,671 Net revenues from contracted payors* 8,004 35,260 Net commercial revenues 25,616 60,931 Development services revenues 240 147 Kits and Specimen Collection Tubes (SCTs) 2 171 Total net revenues $ 25,858 $ 61,249 * Includes Medicare and Medicare Advantage, as reimbursement amounts are fixed.
Summary of Third-Party Payors That Represent More Than 10% of Total Net Revenues and Total Net Accounts Receivable and Their Related Percentage	The Company's third-party payors that represent more than 10% of total net revenues in any period presented during the years ended December 31, 2022 and 2021 were as follows: For the year ended December 31, 2022 2021 Medicare and Medicare Advantage/CARES Act 36 % 56 % Blue Cross Blue Shield 16 % 17 % Kaiser Permanente 16 % 6 % The Company's third-party payors that represent more than 10% of total net accounts receivable as of December 31, 2022 and 2021 were as follows: For the year ended December 31, 2022 2021 Medicare and Medicare Advantage/CARES Act 5 % 31 % Blue Cross Blue Shield 23 % 19 %

Balance Sheet Details (Tables)

Balance Sheet Details (Tables)	12 Months Ended
	Dec. 31, 2022
Balance Sheet Component [Abstract]
Schedule of Balance Sheet Details	The following provides certain balance sheet details (in thousands): December 31, December 31, 2022 2021 Inventories Raw materials $ 1,564 $ 2,486 Subassemblies 401 324 Finished goods 36 42 2,001 $ 2,852 Less: inventory reserve ( 1,244 ) $ ( 201 ) Total inventories, net $ 757 $ 2,651 Fixed Assets Machinery and equipment $ 3,183 $ 3,063 Furniture and office equipment 160 161 Computer equipment and software 3,824 2,931 Leasehold improvements 689 634 Construction in process 39 245 $ 7,895 $ 7,034 Less accumulated depreciation and amortization ( 5,323 ) ( 4,633 ) Total fixed assets, net $ 2,572 $ 2,401 Accrued Liabilities Accrued payroll 605 725 Accrued vacation 799 961 Accrued bonuses 90 178 Accrued sales commissions 52 600 Accrued 401(k) match 220 283 Accrued other 483 271 Total accrued liabilities $ 2,249 $ 3,018

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2022
Leases [Abstract]
Schedule of Lease Expense	The following schedule represents the components of lease expense for the years ended December 31, 2022 and 2021 (in thousands): December 31, December 31, 2022 2021 Lease cost Finance lease cost Amortization of right-of-use assets $ 920 $ 863 Interest on lease liabilities 196 277 Operating lease cost 1,658 1,656 Total $ 2,774 $ 2,796
Schedule Represents Maturities of Operating and Finance Lease Liabilities	The following schedule represents maturities of operating and finance lease liabilities as of December 31, 2022 (in thousands): Finance Operating Minimum Minimum Lease Lease Payments Payments 2023 $ 1,200 $ 1,629 2024 770 1,672 2025 396 1,715 2026 192 1,762 2027 15 1,805 Thereafter - 6,713 Total payments 2,573 15,296 Less amount representing interest ( 274 ) ( 5,603 ) Present value of payments $ 2,299 $ 9,693
Supplemental Cash Flow Information Related to Operating and Finance Leases	The following schedule sets forth supplemental cash flow information related to operating and finance leases as of December 31, 2022 and 2021 (in thousands): December 31, December 31, 2022 2021 Other information Operating cash flows from finance leases $ 196 $ 277 Operating cash flows from operating lease $ 1,586 $ 549 Financing cash flows from finance leases $ 1,305 $ 1,150

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2022
Share-Based Payment Arrangement [Abstract]
Assumptions Used for Determining Fair Value of Stock Options Under Black-Scholes Pricing Model	The assumptions used in the Black-Scholes pricing model for options granted during the years ended December 31, 2022 and 2021 are as follows: 2022 2021 Stock and exercise prices $ 0.74 - $ 2.39 $ 3.62 - $ 6.03 Expected dividend yield 0.00 % 0.00 % Discount rate-bond equivalent yield 0.51 % - 4.36 % 0.52 % - 1.15 % Expected life (in years) 5.50 - 6.03 5.0 - 5.98 Expected volatility 160 % - 180 % 163.1 % - 173.9 %
Summary of Stock Option Activity	A summary of stock option activity for the years ended December 31, 2022 and 2021 is as follows: Number of Weighted Weighted Outstanding at December 31, 2020 1,078,704 $ 11.64 9.36 Granted 1,558,510 $ 3.96 Exercised ( 537 ) 3.14 Cancelled/forfeited/expired ( 256,681 ) $ 7.83 Outstanding at December 31, 2021 2,379,996 $ 7.07 9.06 Granted 1,412,900 $ 2.10 Cancelled/forfeited/expired ( 1,529,495 ) $ 7.28 Outstanding at December 31, 2022 2,263,401 $ 3.85 8.86 Vested and unvested expected to vest, December 31, 2022 2,236,680 $ 3.89 8.81
Effects of Stock-Based Compensation Related to Equity Awards to Employees and Nonemployees on Statement of Operations	The following table presents the effects of stock-based compensation related to equity awards to employees and nonemployees on the statement of operations during the periods presented (in thousands): Years Ended December 31, 2022 2021 Stock Options Cost of revenues $ 628 $ 598 Research and development expenses 300 231 General and administrative expenses 1,860 1,266 Sales and marketing expenses 439 367 Total stock-based compensation $ 3,227 $ 2,462

Common Stock Warrants Outstan_2

Common Stock Warrants Outstanding (Tables)	12 Months Ended
	Dec. 31, 2022
Equity Classified Warrants [Abstract]
Summary of Equity-Classified Common Stock Warrant Activity, for Warrants Other than Underlying Unexercised Overallotment Option Warrants	A summary of equity-classified common stock warrant activity, for warrants other than those underlying unexercised overallotment option warrants, during 2022 and 2021 is as follows: Average Weighted Remaining Number of Average Exercise Contractual Shares Price Per Share Term in Years Outstanding at December 31, 2020 997,167 $ 35.48 3.3 Issued — $ — Exercised ( 126,330 ) $ 3.52 Expired ( 13,576 ) $ 569.89 Outstanding at December 31, 2021 857,261 $ 31.73 2.2 Issued — $ — Exercised — $ — Expired ( 12,801 ) $ 606.22 Outstanding at December 31, 2022 844,460 $ 23.02 1.3

Net Loss per Common Share (Tabl

Net Loss per Common Share (Tables)	12 Months Ended
	Dec. 31, 2022
Earnings Per Share [Abstract]
Schedule of Anti-Dilutive Securities Excluded from Computations of Diluted Weighted-Average Shares	The following potentially dilutive securities have been excluded from the computations of diluted weighted-average shares outstanding for the periods presented, as they would be anti-dilutive: December 31, December 31, 2022 2021 Common warrants outstanding 844,460 857,261 RSUs outstanding - 36 Convertible preferred stock outstanding (number of common stock equivalents) 46,541 46,541 Common options outstanding 2,263,401 2,379,996 Total anti-dilutive common share equivalents 3,154,402 3,283,834

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Schedule of Provision for Income Taxes	For the years ended December 31, 2022 and 2021, the provision for income taxes was calculated as follows (in thousands): December 31, December 31, 2022 2021 Current: Federal $ — $ — State ( 125 ) 125 Total ( 125 ) 125 Deferred Federal — — State — — Total — — Provision for income tax $ ( 125 ) $ 125
Reconciles of Income Taxes Computed at Federal Statutory Rate and Provision for Income Taxes	The following table reconciles income taxes computed at the federal statutory rate and the Company’s provision for income taxes (in thousands): December 31, December 31, 2022 2021 Income tax at statutory rate $ ( 6,766 ) $ ( 567 ) Change in federal tax rate — State liability ( 1,694 ) 66 Permanent items 210 278 Stock compensation 960 178 Warrant inducement — — Expiration of net operating losses 710 594 Research and development credit ( 178 ) ( 377 ) Unrecognized tax benefits 125 2,956 State rate change 76 ( 480 ) Estimated section 382 limitation ( 358 ) ( 485 ) Return to provision ( 132 ) ( 8 ) Other 131 28 Valuation allowance 6,791 ( 2,058 ) Provision for income tax $ ( 125 ) $ 125
Summary of Gross Unrecognized Tax Benefits	The following table summarizes the activity related to our gross unrecognized tax benefits (in thousands): December 31, December 31, 2022 2021 Current: Balance at the beginning of the year $ 3,679 $ — Adjustments related to prior year tax positions 25 3,640 Increases related to current year tax positions 118 39 Decreases for tax positions from prior years — — Provision for income tax $ 3,822 $ 3,679
Summary of Deferred Tax Assets	The tax effects of carryforwards and other temporary differences that give rise to deferred tax assets consist of the following (in thousands): For the year ended December 31, 2022 2021 Estimated net operating loss carryforward $ 23,598 $ 18,482 Estimated research and development credits 1,032 1,026 Capitalized research and development 1,490 470 Accruals and other 3,234 2,046 Operating lease liability 2,648 2,821 Fixed assets 417 368 Stock based compensation 617 1,164 33,036 26,377 Right-of-use asset ( 3,161 ) ( 3,295 ) Gross deferred tax liabilities ( 3,161 ) ( 3,295 ) Less valuation allowance ( 29,875 ) ( 23,082 ) Net deferred tax assets $ — $ —

Liquidity - Additional Informat

Liquidity - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Cash and Cash Equivalents [Abstract]
Cash	$ 12,897	$ 28,864
Accumulated deficit	298,438	266,351
Net losses	(32,087)	(2,824)
Net revenues	$ 25,858	$ 61,249

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2022 USD ($) Segment	Dec. 31, 2021 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Net revenues	$ 25,858,000	$ 61,249,000
Unbilled accounts receivables	$ 800,000	3,500,000
Number of reportable segments | Segment	1
Number of suppliers	one supplier
Depreciation and amortization expense	$ 1,655,000	1,530,000
Impairment losses	0	0
Research and development expenses	6,161,000	4,960,000
Income tax expense	(125,000)	125,000
Accrual for interest or penalties for income taxes	0	0
Interest or penalties expense on income taxes	$ 0	0
Change in inventory reserve		100,000
State [Member]
Summary Of Significant Accounting Policies [Line Items]
Income tax expense		$ 125,000
Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of assets	7 years
Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of assets	3 years
ASC 606 [Member]
Summary Of Significant Accounting Policies [Line Items]
Performance obligation, description of timing	The duration of time between accession receipt and delivery of a valid assay result to the ordering physician or entity is typically less than two weeks, and for our RT-PCR COVID-19 testing, was typically 48 hours or less.
Practical expedient, description	The Company does not adjust the transaction price for the effects of a significant financing component, as at contract inception, the Company expects the collection cycle to be one year or less.
ASC 606 [Member] | Maximum [Member] | Sales and Marketing Expenses [Member]
Summary Of Significant Accounting Policies [Line Items]
Amortization period	1 year

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Composition of Net Revenues Recognized Disaggregated by Source and Nature (Detail) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2022	Dec. 31, 2021
Disaggregation Of Revenue [Line Items]
Total net revenues		$ 25,858	$ 61,249
Commercial Revenues [Member]
Disaggregation Of Revenue [Line Items]
Total net revenues		25,616	60,931
Commercial Revenues [Member] | Contracted Payors [Member]
Disaggregation Of Revenue [Line Items]
Total net revenues	[1]	8,004	35,260
Commercial Revenues [Member] | Non-Contracted Payors [Member]
Disaggregation Of Revenue [Line Items]
Total net revenues		17,612	25,671
Development Services Revenues [Member]
Disaggregation Of Revenue [Line Items]
Total net revenues		240	147
Kits and Specimen Collection Tubes (SCTs)
Disaggregation Of Revenue [Line Items]
Total net revenues		$ 2	$ 171
[1] Includes Medicare and Medicare Advantage, as reimbursement amounts are fixed.

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Summary of Third-Party Payors That Represent More Than 10% of Total Net Revenues and Total Net Accounts Receivable and Their Related Percentage (Detail)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Customer Concentration Risk [Member] | Net Revenues [Member] | Medicare and Medicare Advantage [Member] | Cares Act [Member]
Concentration Risk [Line Items]
Concentration risk percentage	36%	56%
Customer Concentration Risk [Member] | Net Revenues [Member] | Blue Cross Blue Shield [Member]
Concentration Risk [Line Items]
Concentration risk percentage	16%	17%
Customer Concentration Risk [Member] | Net Revenues [Member] | Kaiser Permanente [Member]
Concentration Risk [Line Items]
Concentration risk percentage	16%	6%
Credit Concentration Risk [Member] | Net Accounts Receivable [Member] | Medicare and Medicare Advantage [Member] | Cares Act [Member]
Concentration Risk [Line Items]
Concentration risk percentage	5%	31%
Credit Concentration Risk [Member] | Net Accounts Receivable [Member] | Blue Cross Blue Shield [Member]
Concentration Risk [Line Items]
Concentration risk percentage	23%	19%

Sales of Equity Securities - Ad

Sales of Equity Securities - Additional Information (Detail) - USD ($)		1 Months Ended	12 Months Ended
	May 12, 2021	Jan. 31, 2020	Dec. 31, 2022	Dec. 31, 2021	Jan. 31, 2018
Class Of Stock [Line Items]
Proceeds from exercise of common stock warrants				$ 28,000
Fair value of warrants issued		$ 1,900,000
Warrant inducement expense				$ 2,100,000
Sales Agreement [Member] | Sales Agent [Member]
Class Of Stock [Line Items]
Stock price			$ 1.29	$ 4.31
Shares issued in offering			219,910	3,428,680
Percentage of fixed commission to sales agent rate equal to gross sales price per share of common stock sold under sales agreement	3%
Net cash proceeds from sale of securities			$ 200,000	$ 14,100,000
Maximum [Member] | Sales Agreement [Member] | Sales Agent [Member]
Class Of Stock [Line Items]
Shares issued in offering	25,000,000
Warrant [Member]
Class Of Stock [Line Items]
Issuance of warrants to purchase shares of common stock					89,657
Stock price		$ 3.495			$ 4.05
Over-allotment Option [Member] | Warrant [Member]
Class Of Stock [Line Items]
Proceeds from exercise of common stock warrants		$ 700,000
Shares issued in offering		192,750
February 2019 March 2019 Warrant Repricing and Exchange Transaction [Member]
Class Of Stock [Line Items]
Proceeds from exercise of common stock warrants		$ 2,300,000
Number of warrants issued under warrant repricing and exchange transaction		692,725
Warrant inducement expense		$ 191,000
February 2019 March 2019 Warrant Repricing and Exchange Transaction [Member] | Warrant [Member]
Class Of Stock [Line Items]
Issuance of warrants to purchase shares of common stock		692,725

Balance Sheet Details - Schedul

Balance Sheet Details - Schedule of Balance Sheet Details (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Inventories
Raw materials	$ 1,564	$ 2,486
Subassemblies	401	324
Finished goods	36	42
Inventory, gross	2,001	2,852
Less: inventory reserve	(1,244)	(201)
Total inventories, net	757	2,651
Fixed Assets
Machinery and equipment	3,183	3,063
Furniture and office equipment	160	161
Computer equipment and software	3,824	2,931
Leasehold improvements	689	634
Construction in process	39	245
Total fixed assets, gross	7,895	7,034
Less accumulated depreciation and amortization	(5,323)	(4,633)
Total fixed assets, net	2,572	2,401
Accrued Liabilities
Accrued payroll	605	725
Accrued vacation	799	961
Accrued bonuses	90	178
Accrued sales commissions	52	600
Accrued 401(k) match	220	283
Accrued other	483	271
Total accrued liabilities	$ 2,249	$ 3,018

Leases - Additional Information

Leases - Additional Information (Detail)		12 Months Ended
	Jun. 01, 2020 USD ($) ft²	Dec. 31, 2022 USD ($) mo	Dec. 31, 2021 USD ($) mo	Dec. 31, 2020 USD ($)
Leases [Line Items]
Financed equipment		$ 7,200,000	$ 6,000,000
Accumulated depreciation related to equipment under finance leases		4,100,000	3,200,000
Depreciation expense related to equipment under finance leases		900,000	900,000
Total amount from equipment financing commitment		$ 1,100,000	$ 1,200,000
Finance lease transaction, frequency of payments		monthly	months
Finance lease transaction, monthly installments of principal and interest payments		$ 20,000
Finance lease transaction, total amount to be repaid		$ 900,000	$ 1,600,000
Finance lease transaction, commitment period		2027-08	2026-03
Operating lease monthly payments		$ 1,586,000	$ 549,000
Operating lease, right-of-use asset		8,486,000	9,026,000
Operating lease liability		$ 9,693,000
Finance lease, weighted average remaining lease term		2 years 6 months 18 days
Operating lease, weighted average remaining lease term		8 years 6 months
Finance lease, weighted average discount rate, percent		9.07%
Operating lease, weighted average discount rate, percent		12%
9955 Mesa Rim Road in San Diego, California [Member]
Leases [Line Items]
Lease agreement | ft²	39,000
Lease commenced date	Dec. 01, 2020
Lessee, operating lease, term of contract	127 months
Lease term, description		The lease included a rent abatement period of seven months, from January 2021 through July of 2021, during which period the Company was exempt from paying the amount of base rent of $111,000.
Rent Expense	$ 111,000
Leasehold improvement allowance	1,600,000
Additional leasehold improvement allowance	$ 1,600,000
Additional rent payment of percentage	7%
Additional rent payment	$ 18,000
Lessee operating lease initial monthly lease payments	140,000
Reimbursable leasehold improvement costs			$ 1,800,000	$ 1,600,000
Operating lease monthly payments	$ 128,000
Operating lease, right-of-use asset				9,800,000
Operating lease liability				$ 9,800,000
Operating lease incremental borrowing rate				12%
Minimum [Member]
Leases [Line Items]
Financed equipment useful life		5 years
Finance lease transaction, number of installments payments | mo		36	36
Maximum [Member]
Leases [Line Items]
Financed equipment useful life		7 years
Finance lease transaction, number of installments payments | mo		60	60

Leases - Schedule of Lease Expe

Leases - Schedule of Lease Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Finance lease cost
Amortization of right-of-use assets	$ 920	$ 863
Interest on lease liabilities	196	277
Operating lease cost	1,658	1,656
Total	$ 2,774	$ 2,796

Leases - Schedule Represents Ma

Leases - Schedule Represents Maturities of Operating and Finance Lease Liabilities (Detail) $ in Thousands	Dec. 31, 2022 USD ($)
Financing Lease Minimum Payment Abstract
2023	$ 1,200
2024	770
2025	396
2026	192
2027	15
Total payments	2,573
Less amount representing interest	(274)
Present value of payments	2,299
Operating Lease Minimum Payment Abstract
2023	1,629
2024	1,672
2025	1,715
2026	1,762
2027	1,805
Thereafter	6,713
Total payments	15,296
Less amount representing interest	(5,603)
Present value of payments	$ 9,693

Leases - Supplemental Cash Flow

Leases - Supplemental Cash Flow Information Related to Operating and Finance Leases (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Other information
Operating cash flows from finance leases	$ 196	$ 277
Operating cash flows from operating leases	1,586	549
Financing cash flows from finance leases	$ 1,305	$ 1,150

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail)			12 Months Ended
	Mar. 22, 2022 shares	Feb. 14, 2022 shares	Dec. 31, 2022 USD ($) Plan shares	Dec. 31, 2021 USD ($)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of equity incentive plans | Plan			2
Unrecognized share-based compensation expense, weighted-average recognition period			2 years 5 months 15 days
Stock Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period			10 years
Option awards assumptions, method used			Black-Scholes pricing model
Intrinsic value of options outstanding			$ 0	$ 610
Intrinsic value of options exercisable			0	610
Intrinsic value of options vested and unvested expected to vest			$ 0	$ 610
Stock Options [Member] | Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period			4 years
Employee Stock Option One [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Time period for vesting grants in installments on monthly basis			monthly thereafter for the remaining three years
Employee Stock Option Two [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options vesting term			monthly vesting beginning month-one after the grant and monthly thereafter
Stock Options and RSUs [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized share-based compensation expense, stock options			$ 3,700,000
Options Vesting on One Year Anniversary [Member] | Stock Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of Overall Stock Grant Subject to Vesting			25%
2013 Equity Incentive Plan [Member] | Non-inducement Shares [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Increase in number of shares of common stock authorized for issuance | shares			1,300,000
2013 Equity Incentive Plan [Member] | Inducement Shares [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Increase in number of shares of common stock authorized for issuance | shares	500,000	1,000,000

Stock-Based Compensation - Assu

Stock-Based Compensation - Assumptions Used for Determining Fair Value of Stock Options Under Black-Scholes Pricing Model (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected dividend yield	0%	0%
Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock and exercise prices	$ 0.74	$ 3.62
Discount rate-bond equivalent yield	0.51%	0.52%
Expected life (in years)	5 years 6 months	5 years
Expected volatility	160%	163.10%
Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock and exercise prices	$ 2.39	$ 6.03
Discount rate-bond equivalent yield	4.36%	1.15%
Expected life (in years)	6 years 10 days	5 years 11 months 23 days
Expected volatility	180%	173.90%

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Stock Option Activity (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Share-Based Payment Arrangement [Abstract]
Number of Shares Outstanding, Beginning Balance	2,379,996	1,078,704
Number of Shares, Granted	1,412,900	1,558,510
Number of Shares, Exercised		(537)
Number of Shares, Cancelled/forfeited/expired	(1,529,495)	(256,681)
Number of Shares Outstanding, Ending Balance	2,263,401	2,379,996	1,078,704
Number of Shares, Vested and unvested expected to vest, Ending Balance	2,236,680
Weighted Average Exercise Price Per Share, Outstanding, Beginning Balance	$ 7.07	$ 11.64
Weighted Average Exercise Price Per Share, Granted	2.10	3.96
Weighted Average Exercise Price Per Share, Exercised		3.14
Weighted Average Exercise Price Per Share, Cancelled/forfeited/expired	7.28	7.83
Weighted Average Exercise Price Per Share, Outstanding, Ending Balance	3.85	$ 7.07	$ 11.64
Weighted Average Exercise Price Per Share, Vested and unvested expected to vest, Ending Balance	$ 3.89
Weighted Average Remaining Contractual Term in Years, Outstanding	8 years 10 months 9 days	9 years 21 days	9 years 4 months 9 days
Weighted Average Remaining Contractual Term in Years, Vested and unvested expected to vest	8 years 9 months 21 days

Stock-Based Compensation - Effe

Stock-Based Compensation - Effects of Stock-Based Compensation Related to Equity Awards to Employees and Nonemployees on Statement of Operations (Detail) - Stock Options [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	$ 3,227	$ 2,462
Cost of revenues [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	628	598
Research and Development Expenses [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	300	231
General and Administrative Expenses [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	1,860	1,266
Sales and Marketing Expenses [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	$ 439	$ 367

Common Stock Warrants Outstan_3

Common Stock Warrants Outstanding - Summary of Equity-Classified Common Stock Warrant Activity, for Warrants Other than Underlying Unexercised Overallotment Option Warrants (Detail) - Warrants [Member] - $ / shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Class Of Warrant Or Right [Line Items]
Number of Shares, Outstanding, Beginning Balance	857,261	997,167
Number of Shares, Exercised		(126,330)
Number of Shares, Expired	(12,801)	(13,576)
Number of Shares, Outstanding, Ending Balance	844,460	857,261	997,167
Weighted Average Exercise Price Per Share, Outstanding, Beginning Balance	$ 31.73	$ 35.48
Weighted Average Exercise Price Per Share, Exercised		3.52
Weighted Average Exercise Price Per Share, Expired	606.22	569.89
Weighted Average Exercise Price Per Share, Outstanding, Ending Balance	$ 23.02	$ 31.73	$ 35.48
Average Remaining Contractual Term (in years)	1 year 3 months 18 days	2 years 2 months 12 days	3 years 3 months 18 days

Common Stock Warrants Outstan_4

Common Stock Warrants Outstanding - Additional Information (Detail) - USD ($)	1 Months Ended
	Jan. 31, 2020	Dec. 31, 2019	May 31, 2019	Mar. 31, 2019	Feb. 28, 2019	Dec. 31, 2022	Dec. 31, 2021
Class Of Warrant Or Right [Line Items]
Common stock warrants outstanding, intrinsic value						$ 0	$ 16,000
Warrants [Member] | February 2019 Financing Transaction [Member]
Class Of Warrant Or Right [Line Items]
Class of warrant or rights, expiration date					Feb. 12, 2024
Warrants [Member] | March 2019 Transaction [Member]
Class Of Warrant Or Right [Line Items]
Class of warrant or rights, expiration date				Sep. 19, 2024
Warrants [Member] | May 2019 Inducement Offering [Member]
Class Of Warrant Or Right [Line Items]
Class of warrant or rights, expiration date			Dec. 02, 2024
Warrants [Member] | December 2019 Underwritten Offering [Member]
Class Of Warrant Or Right [Line Items]
Class of warrant or rights, expiration date		Dec. 11, 2024
Warrants [Member] | January 2020 Inducement Offering [Member]
Class Of Warrant Or Right [Line Items]
Class of warrant or rights, expiration date	Jul. 10, 2025

Net Loss per Common Share - Sch

Net Loss per Common Share - Schedule of Anti-Dilutive Securities Excluded from Computations of Diluted Weighted-Average Shares (Detail) - shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive common share equivalents	3,154,402	3,283,834
Convertible Preferred Stock Outstanding [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive common share equivalents	46,541	46,541
Common Warrants Outstanding [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive common share equivalents	844,460	857,261
RSUs [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive common share equivalents		36
Common Options Outstanding [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive common share equivalents	2,263,401	2,379,996

Income Taxes - Schedule of Prov

Income Taxes - Schedule of Provision for Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Current:
State	$ (125)	$ 125
Total	(125)	125
Deferred
Provision for income tax	$ (125)	$ 125

Income Taxes - Reconciles of In

Income Taxes - Reconciles of Income Taxes Computed at Federal Statutory Rate and Provision for Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Income tax at statutory rate	$ (6,766)	$ (567)
State liability	(1,694)	66
Permanent items	210	278
Stock compensation	960	178
Expiration of net operating losses	710	594
Research and development credit	(178)	(377)
Unrecognized tax benefits	125	2,956
State rate change	76	(480)
Estimated section 382 limitation	(358)	(485)
Return to provision	(132)	(8)
Other	131	28
Valuation allowance	6,791	(2,058)
Provision for income tax	$ (125)	$ 125

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Tax Contingency [Line Items]
Percent of uncertain income tax positions recognized	50%	50%
Percentage of change in ownership	50%
Period of change in ownership	3 years
Capitalized research and development costs	$ 5.2
Net operating loss carryforwards	$ 10.6
Net operating loss carryforwards, expiration year	will begin to expire in 2023
Federal [Member]
Income Tax Contingency [Line Items]
Net operating loss carryforwards	$ 91.3	$ 80.7
Net operating loss carryforwards, expiration year	carrying forward indefinitely
Federal [Member] | Research Tax Credit Carryforward [Member]
Income Tax Contingency [Line Items]
Research and development tax credits	$ 1
Income tax research and development expiration year	will begin to expire in 2023
Federal [Member] | Maximum [Member]
Income Tax Contingency [Line Items]
Percentage of future taxable income offset by operating loss carryforwards	80%
California [Member]
Income Tax Contingency [Line Items]
Net operating loss carryforwards, expiration year	will begin to expire in 2027
Additional net operating loss carryforwards	$ 66.8	$ 63.2	$ 3.6
California [Member] | Research Tax Credit Carryforward [Member]
Income Tax Contingency [Line Items]
Research and development tax credits	$ 4
California [Member] | Maximum [Member]
Income Tax Contingency [Line Items]
Percentage of future taxable income offset by operating loss carryforwards	80%

Income Taxes - Summary of Gross

Income Taxes - Summary of Gross Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Balance at the beginning of the year	$ 3,679
Adjustments related to prior year tax positions	25	$ 3,640
Increases related to current year tax positions	118	39
Provision for income tax	$ 3,822	$ 3,679

Income Taxes - Summary of Defer

Income Taxes - Summary of Deferred Tax Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Estimated net operating loss carryforward	$ 23,598	$ 18,482
Estimated research and development credits	1,032	1,026
Capitalized research and development	1,490	470
Accruals and other	3,234	2,046
Operating lease liability	2,648	2,821
Fixed assets	417	368
Stock based compensation	617	1,164
Gross deferred tax assets	33,036	26,377
Right-of-use asset	(3,161)	(3,295)
Gross deferred tax liabilities	(3,161)	(3,295)
Less valuation allowance	$ (29,875)	$ (23,082)

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Aegea Biotechnologies, Inc [Member]
Related Party Transaction [Line Items]
Reimbursement for shared patent costs	$ 0	$ 49,000

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) $ in Millions	1 Months Ended
	Jun. 30, 2022 USD ($)
Sales and Marketing Expense [Member]
Loss Contingencies [Line Items]
Loss contingency accrual, payments	$ 1.7

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands			3 Months Ended	12 Months Ended
	Jan. 06, 2023	Jan. 01, 2023	Mar. 31, 2023	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Subsequent Event [Line Items]
Net proceeds from issuance of common stock					$ 240	$ 14,120
Subsequent Event [Member]
Subsequent Event [Line Items]
Percentage of reduction in workforce	36%
Subsequent Event [Member] | At-the-market Equity Facility [Member]
Subsequent Event [Line Items]
Shares issued in offering		707,114
Stock price		$ 0.57
Net proceeds from issuance of common stock		$ 400
Scenario Forecast [Member]
Subsequent Event [Line Items]
Severance and other employee termination-related costs			$ 800
Scenario Forecast [Member] | Separation Agreement [Member]
Subsequent Event [Line Items]
Severance and other employee termination-related costs				$ 100