- --------------------------------------------------------------------------------

                                 UNITED STATES
                      SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C. 20549

                            -----------------------

                                   FORM 10-Q

               QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d)
                    OF THE SECURITIES EXCHANGE ACT OF 1934

                            -----------------------

                 For the Quarterly Period Ended March 31, 2001

                       Commission File Number 000-21930

                         BIOSOURCE INTERNATIONAL, INC.

            (Exact name of Registrant as specified in its charter)

               Delaware                                   77-0340829
    (State or other jurisdiction of                    (I.R.S. Employer
     incorporation or organization)                   Identification No.)


   542 Flynn Road, Camarillo, California                    93012
  (Address of principal executive offices)                (Zip Code)


      Registrant's telephone number, including area code: (805) 987-0086


     Indicate by check mark whether the Registrant (1) has filed all reports
required to be filed by Section 13 or 15(d) of the Securities Exchange Act of
1934 during the preceding 12 months (or for such shorter periods that the
Registrant was required to file such reports), and (2) has been subject to such
filing requirements for the past 90 days.

                      YES   X                      NO ____
                           ----


     The number of shares of the Registrant's common stock, $.001 par value,
outstanding as of May 7, 2001 was 10,434,717.

- --------------------------------------------------------------------------------


                BIOSOURCE INTERNATIONAL, INC. AND SUBSIDIARIES
FORM 10-Q
                                 March 31, 2001
                                     INDEX



                                                                                     Page No.
                                                                                     --------
                                                                                  
                           Part I. Financial Information

Item 1.  Financial Statements

               Condensed Consolidated Balance Sheets as of  March 31, 2001
               (unaudited) and December 31, 2000                                          3

               Condensed Consolidated Statements of Operations for the three
               months ended  March 31, 2001 and 2000 (unaudited)                          4

               Condensed Consolidated Statements of Cash Flows for the three
               months ended March 31, 2001 and 2000 (unaudited)                           5

               Notes to Condensed Consolidated Unaudited Financial Statements             6

Item 2.  Management's Discussion and Analysis of
         Financial Condition and Results of Operations                                   10

Item 3.  Quantitative and Qualitative Disclosures about Market Risk                      22


                            Part II. Other Information

Item 1.  Legal Proceedings                                                               23

Item 2.  Changes in Securities and Use of Proceeds                                       23

Item 3.  Defaults Upon Senior Securities                                                 23

Item 4.  Submission of Matters to a Vote of Security Holders                             23

Item 5.  Other Information                                                               23

Item 6.  Exhibits and Reports on Form 8-K                                                23

Signatures                                                                               24


                                       2


                BIOSOURCE INTERNATIONAL, INC. AND SUBSIDIARIES
                     CONDENSED CONSOLIDATED BALANCE SHEETS
               (Amounts in thousands, except for share amounts)



                                                                                            March 31,       December 31,
                                                                                              2001              2000
                                                                                           -----------      -----------
                                                                                            (Unaudited)
                                                                                                      
                             ASSETS
Current assets:
   Cash and cash equivalents                                                              $   9,457.1          10,632.6
   Accounts receivable, less allowance for doubtful accounts
     of $136.3 at March 31, 2001 and $142.8 at December 31, 2000                              6,029.8           5,611.2
   Inventories, net (note 3)                                                                  6,311.8           6,693.0
   Prepaid expenses and other current assets                                                  1,325.1           1,261.4
   Deferred income taxes                                                                      2,222.0           2,222.0
                                                                                          -----------         ---------
                            Total current assets                                             25,345.8          26,420.2

Property and equipment, net (note 4)                                                          4,022.5           4,353.0
Intangible assets net of accumulated amortization of $2,553.5 at March 31, 2001
   and $2,278.9 at December 31, 2000                                                         12,476.9          12,751.5
Other assets                                                                                    384.1             382.4
Deferred tax assets                                                                           6,457.1           6,457.1
                                                                                          -----------         ---------
                                                                                          $  48,686.4          50,364.2
                                                                                          ===========         =========

               LIABILITIES AND STOCKHOLDERS EQUITY
Current liabilities:
   Accounts payable                                                                       $   1,942.1           3,275.1
   Accrued expenses                                                                           2,168.0           2,687.7
   Deferred income                                                                              330.4             314.2
   Income tax payable                                                                               -              41.1
                                                                                          -----------         ---------
                            Total current liabilities                                         4,440.5           6,318.1

Commitments and contingencies (note 8)

Stockholders' equity:

Common stock, $.001 par value. Authorized 20,000,000 shares: issued
           10,690,290 shares and outstanding 10,399,859 shares at March 31,
           2001; issued 10,616,889 shares and outstanding 10,326,458 shares at
           December 31, 2000                                                                     10.4              10.3
Additional paid-in capital                                                                   49,843.2          49,303.9
Accumulated deficit                                                                          (3,120.8)         (3,071.1)
Accumulated other comprehensive loss                                                         (2,486.9)         (2,197.0)
                                                                                          -----------         ---------
                            Net stockholders' equity                                         44,245.9          44,046.1
                                                                                          -----------         ---------
                                                                                          $  48,686.4          50,364.2
                                                                                          ===========         =========


The accompanying notes are an integral part of these condensed consolidated
financial statements

                                       3


                BIOSOURCE INTERNATIONAL, INC. AND SUBSIDIARIES
                CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS
                  Three Months Ended March 31, 2001 and 2000
                 (Amounts in thousands, except per share data)
                                  (Unaudited)



                                                            -----------------------------
                                                               2001             2000
                                                            ------------    -------------
                                                                      
Net sales                                                 $     8,657.2          7,891.4
Cost of sales                                                   3,957.5          3,058.3
                                                            ------------    -------------
    Gross profit                                                4,699.7          4,833.1

Operating expenses:
    Research and development                                      953.5            822.4
    Sales and marketing                                         1,922.2          1,346.4
    General and administrative                                  1,807.2          1,092.2
    Amortization of Intangibles                                   274.6            269.4
                                                            ------------    -------------
         Total operating expenses                               4,957.5          3,530.4
                                                            ------------    -------------
Operating income (loss)                                          (257.8)         1,302.7

Interest income (expense), net                                    136.5           (182.4)
Other income, net                                                  49.3             15.9
                                                            ------------    -------------
Income (loss) before income taxes (benefit)                       (72.0)         1,136.2
Income tax expense (benefit)                                      (22.3)           352.2
                                                            ------------    -------------
        Net income (loss)                                         (49.7)           784.0
Redeemable preferred stock dividend and accretion
  of beneficial conversion                                            -         (1,146.8)
                                                            ------------    -------------
Net loss available to common stockholders                 $       (49.7)          (362.8)
                                                            ============    =============

Net loss per share available to common stockholders
    Basic                                                 $       (0.00)           (0.05)
                                                            ============    =============
    Diluted                                               $       (0.00)           (0.05)
                                                            ============    =============
Shares used to compute net loss per share available
  to common stockholders
    Basic                                                      10,351.7          7,717.3
                                                            ============    =============
    Diluted                                                    10,351.7          7,717.3
                                                            ============    =============


The accompanying notes are an integral part of these condensed consolidated
financial statements

                                       4


                BIOSOURCE INTERNATIONAL, INC. AND SUBSIDIARIES
                CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS
                  Three Months Ended March 31, 2001 and 2000
                            (Amounts in thousands)
                                  (Unaudited)



                                                                                -------------------------------
                                                                                    2001              2000
                                                                                -------------     -------------
                                                                                            
Cash flows from operating activities:
      Net income (loss)                                                         $      (49.7)            784.0
      Adjustments to reconcile net income (loss) to net
        cash provided by operating activities:
           Depreciation and amortization                                               551.6             510.4
           Stock compensation                                                          339.0                 -
      Changes in assets and liabilities
           Accounts receivable                                                        (642.3)           (839.6)
           Inventories                                                                 232.8            (319.3)
           Prepaid expenses and other current assets                                   (66.9)           (168.2)
           Other assets                                                                365.4             (10.8)
           Accounts payable                                                         (1,007.7)           (420.9)
           Accrued expenses                                                           (475.4)           (262.3)
           Deferred income                                                             (50.8)            (61.4)
           Income tax payable                                                            6.4             277.7
                                                                                ------------      ------------
           Net cash used in operating activities                                      (797.6)           (510.4)
                                                                                ------------      ------------

Cash flows from investing activities:
      Purchase of property and equipment                                              (213.3)           (202.4)
                                                                                ------------      ------------
           Net cash used in investing activities                                      (213.3)           (202.4)
                                                                                ------------      ------------

Cash flows from financing activities:
      Proceeds from the exercise of options                                            200.5           1,362.1
      Proceeds from the exercise of warrants                                               -             750.0
      Proceeds from the issuance of preferred stock                                        -           8,461.5
      Repayments to bank                                                                   -         (12,773.1)
      Payments on capital lease obligations                                                -             (13.3)
                                                                                ------------      ------------
           Net cash provided by (used) in financing activities                         200.5          (2,212.8)
                                                                                ------------      ------------

           Net decrease in cash and cash equivalents                                  (810.4)         (2,925.6)
Effect of exchange rates on cash and cash equivalents                                 (365.1)            (92.7)

Cash and cash equivalents at beginning of period                                    10,632.6           4,644.5

                                                                                ------------      ------------
Cash and cash equivalents at end of period                                      $    9,457.1           1,626.2
                                                                                ============      ============

Supplemental disclosure of cash flow information:
    Cash paid during the period for:
           Interest                                                             $        0.7             264.0
                                                                                ============      ============
           Income taxes                                                         $          -              22.0
                                                                                ============     =============


The accompanying notes are an integral part of these condensed consolidated
financial statements.

                                       5


BIOSOURCE INTERNATIONAL, INC. AND SUBSIDIARIES
Notes to Condensed Consolidated Unaudited Financial Statements

1.   Basis of Presentation

     The accompanying condensed consolidated financial statements are unaudited
and have been prepared pursuant to the rules and regulations of the Securities
and Exchange Commission regarding interim financial reporting. Accordingly, they
do not include all of the information and footnotes required by generally
accepted accounting principles for complete financial statements and should be
read in conjunction with the consolidated financial statements and notes thereto
included in our Annual Report on Form 10-K, for the fiscal year ended December
31, 2000. In the opinion of management, the accompanying condensed consolidated
unaudited financial statements include all adjustments, which are necessary for
a fair presentation. The results of operations for the three months ended March
31, 2001 are not necessarily indicative of results to be expected for the full
fiscal year.

2.   General

     Our company develops, manufactures, markets and distributes products and
services that are widely used in biomedical research. Our products and services
enable scientists to better understand the biochemistry, immunology and cell
biology of the human body, aging and certain diseases such as cancer, arthritis
and other inflammatory diseases, AIDS and certain other infectious diseases. We
have a wide variety of products, including immunoassay and ELISA test kits;
immunological reagents, including bioactive proteins (cytokines, growth factors
and adhesion molecules), oligonucleotides, and monoclonal and polyclonal
antibodies. We also manufacture and market custom oligonucleotides, peptides and
antibodies to the specifications of our customers. We use recombinant DNA
technology to produce cytokines and other proteins.

     Our principal offices are located at 542 Flynn Road, Camarillo,
California, 93012, and our telephone number is (805) 383-5200.

3.   Inventories (amounts in thousands)

                                                March 31, 2001   Dec. 31, 2000
                                               ---------------   -------------

               Raw materials...............    $       1,836.3        1,921.3
               Work in process.............              379.2          553.3
               Finished goods..............            4,096.3        4,218.4
                                               ---------------   ------------
                                               $       6,311.8        6,693.0
                                               ===============   ============

4.   Property and Equipment (amounts in thousands)



                                                       March 31, 2001    Dec. 31, 2000
                                                      -----------------  ---------------
                                                                   
          Machinery and equipment.................    $         5,156.0          5,356.4
          Office furniture and equipment..........              2,244.4          2,154.6
          Leasehold improvements..................                760.3            778.7
                                                      -----------------  ---------------
                                                                8,160.7          8,289.7
          Less accumulated depreciation and
          amortization............................              4,138.2          3,936.7
                                                      -----------------  ---------------
                                                      $         4,022.5          4,353.0
                                                      =================  ===============


                                       6


5.   Earnings per Share

          The reconciliation of basic to diluted weighted average shares is as
               follows (amounts in thousands):


                                                       Three Months ended
                                                            March 31,
                                                    ------------------------
                                                       2001         2000
                                                    -----------  -----------
          Net loss available to
              common stockholders                    $    (49.7)      (362.8)
                                                    ===========  ===========

          Weighted average shares used in
              basic computation                        10,351.7      7,717.3

          Dilutive stock options and warrants                 -            -

          Weighted average shares used for
                                                    -----------  -----------
              diluted computation                      10,351.7      7,717.3
                                                    ===========  ===========


     Options to purchase 2,601,887 and 1,656,039 shares at a weighted average
exercise price of $11.42 and $3.29 per share were outstanding as of March 31,
2001 and 2000, respectively, but were not used in the computation of fully
diluted net income (loss) because their effect would be anti-dilutive.

     Warrants to purchase 1,287,700 and 1,346,750 shares at a weighted average
exercise price of $7.77 and $7.91 per share were outstanding as of March 31,
2001 and 2000 respectively but were not included in the computation of diluted
net income (loss) per share because the effect would be anti-dilutive.

6.       Stockholders' Equity

     a)  Comprehensive loss is determined as follows (amounts in thousands):

                                                              Three Months ended
                                                                   March 31,
                                                              ------------------
                                                                2001      2000
                                                              --------  --------

               Net loss available to common
                   stockholders used for basic and diluted
                   loss per share                             $ (49.7)   (362.8)

               Foreign currency translation
               adjustments                                     (289.9)   (258.7)
                                                              -------    ------

               Total comprehensive loss                       $(339.6)   (621.5)
                                                              =======    ======

                                       7


7.   Business Segments

     The Company is engaged in a single industry, the licensing, development,
manufacture, marketing and distribution of immunological reagents, test kits and
oligonucleotides used in biomedical research and human diagnostics. Our
customers are not concentrated in any specific geographic region and no single
customer accounts for a significant amount of our sales.

     Management of the Company has determined its reportable segments are
strategic business units that offer both sales to external customers from
geographic company facilities and sales to external customers in certain
geographic regions. Significant reportable business segments are the United
States and European facilities, and sales to external customers are summarized
as those located in the United States, Europe, Japan and other. We evaluate
performance for the "Sales-from" segments on net revenue and profit and loss
from operations. Our reportable segments are strategic business units that offer
geographical product availability. They are managed separtely because each
business requires different marketing and distribution strategies. Business
information is summarized as follows:

               Sales-from Segments (amounts in thousands):

                                                          Three months ended
                                                               March 31,
                                                            2001       2000
                                                         ----------  ---------
               Net sales to external customers from:
                   United States:
                      Domestic                           $  4,797.4    4,441.6
                      Export                                1,275.7    1,188.2
                                                         ----------  ---------
                          Total United States               6,073.1    5,629.8
                   Europe                                   2,584.1    2,261.6
                                                         ----------  ---------
                          Consolidated                   $  8,657.2    7,891.4
                                                         ==========  =========

               Operating income (loss):
                      United States                      $   (808.3)     899.8
                      Europe                                  550.5      402.9
                                                         ----------  ---------
                          Consolidated                   $   (257.8)   1,302.7
                                                         ==========  =========
               Sales-to Segments:
               Net sales to external customers in:
                      United States                         4,797.4    4,441.6
                      Europe                                2,395.3    2,189.6
                      Japan                                   887.4      864.5
                      Other                                   577.1      395.7
                                                         ----------  ---------
                          Consolidated                   $  8,657.2    7,891.4
                                                         ==========  =========


8.   Commitments and Contingencies

     On June 14, 2000, one of our former employees, Jordan Fishman, Ph.D., filed
a legal action against us in the United States Central District Court of
California. Mr. Fishman's complaint asserts a number of claims for relief
against BioSource and alleges that BioSource breached Mr. Fishman's employment
agreement by failing to register his stock options on a Form S-8 Registration
Statement by December 8, 1999. Second, Fishman claims that this breach, coupled
with BioSource's representations regarding a planned public offering (which
prevented Company insiders from trading in the Company's common stock) and
BioSource's subsequent termination of Fishman's employment, were each part of a
larger scheme to

                                       8


interfere with, and ultimately prevent, the sale of his common stock. On August
11, 2000, we filed a motion to dismiss five of Mr. Fishman's six causes of
action, and on September 29, 2000, the court dismissed three of the causes. On
October 4, 2000, Mr. Fishman filed a first amended complaint. BioSource moved to
dismiss two of the remaining causes of action, one based on new California
Supreme Court precedent, and the other based on deficiencies in Mr. Fishman's
allegations. The Court granted BioSource's motion as to both of these causes of
action. As a consequence, the only two remaining causes of action in this
litigation are (1) breach of contract and (2) fraud. On October 23, 2000,
counsel for Fishman and BioSource conducted their Early Meeting of Counsel where
they exchanged documents and agreed upon discovery and motion cut-off dates,
trial estimates, and exchanged initial witness lists. In December 2000,
BioSource answered the First Amended Complaint, and filed a counter-claim
against Jordan Fishman. The parties are conducting depositions and other
discovery. The case is scheduled for trial commencing July 17, 2001. No
substantive adjudication of Mr. Fishman's claims has yet occurred, however, the
Company believes that it has substantial defenses to Fishman's remaining causes
of action.

     The Company has also commenced an arbitration proceeding against the former
shareholders of its QCB division, including Mr. Fishman, to recover damages
management believes it has suffered in connection with misrepresentations and
omissions made by those shareholders in the representations and warranties
contained in the original Stock Purchase Agreement for QCB executed on December
9, 1998. The Company's claim to recover the $1,347,000 of Escrowed Funds is
based on QCB's breach of the representations and warranties made in the Stock
Purchase Agreement. The parties have selected a panel of three arbitrators who
will hear the dispute in November, 2001. The Company has also asserted a claim
for punitive damages against Jordan Fishman in the arbitration. Management
believes the ultimate outcome will not have a material effect on the
consolidated financial statements.

                                       9


Item 2. Management's Discussion and Analysis of Financial Condition and Results
of Operations


    This discussion and analysis of financial condition and results of
operations should be read in conjunction with the consolidated financial
statements, the notes thereto and other information, including information set
forth in our 10-K for the fiscal year ended December 31, 2000, and all other
recent filings we have made with the Securities and Exchange Commission.

    This Form 10-Q contains forward-looking statements, which are made pursuant
to the safe-harbor provisions of the Private Securities Litigation Reform Act of
1995. Within this Form 10-Q, words such as "believes", "designed",
"anticipates", and similar expressions are intended to identify forward-looking
statements, but are not the exclusive means of identifying such statements.
These forward-looking statements involve a number of risks and uncertainties,
including the timely development and market acceptance of our products and
technologies and other factors described throughout this Form 10-Q and in our
other filings with the Securities and Exchange Commission. The actual results
that we achieve may differ from any forward-looking statements due to such risks
and uncertainties. We do not undertake any obligation to revise or update any
forward-looking statements in order to reflect events or circumstances that may
arise after the date of this report.

Overview

    Our company develops, manufactures, markets and distributes products and
services that are widely used in biomedical research. Our products and services
enable scientists to better understand the biochemistry, immunology and cell
biology of the human body, aging and certain diseases such as cancer, arthritis
and other inflammatory diseases, AIDS and certain other infectious diseases. We
have a wide variety of products, including immunoassay and ELISA test kits;
immunological reagents, including bioactive proteins (cytokines, growth factors
and adhesion molecules), oligonucleotides, and monoclonal and polyclonal
antibodies. We also manufacture and market custom oligonucleotides, peptides and
antibodies to the specifications of our customers. We use recombinant DNA
technology to produce cytokines and other proteins. We have registered our
analyte specific reagents with the FDA and have received a license to sell these
products as Class I Medical Devices. We market these products to in vitro
diagnostic manufacturers and clinical reference laboratories as "active
ingredients" in the tests they produce to identify various specific diseases or
conditions. In order to market these products as medical devices, we are
required to be in compliance with the FDA's Current Good Manufacturing Practices
and Regulations.

Results of operations for the three months ended March 31, 2001

Revenues: Net sales for the three months ended March 31, 2001 and 2000 were
$8,657,200 and $7,891,400, respectively, representing an increase of $765,800 or
9.7% (11.3% in local currency) in 2001 as compared to 2000. Geographically, our
sales for the three months ended March 31, 2001 to customers in the North
America increased by 9.5% due primarily to increased sales of assays, signal
transduction products, custom antibodies and proteins. European sales increased
9.4% (15.3% in local currency) for the three months ended March 31, 2001 as
compared to the quarter ended March 31, 2000 due primarily to increased sales of
assays and signal transduction products. Sales in the rest of the world
increased 11.1% for the three months ended March 31, 2001 as compared to the
comparable prior year period, due primarily to the Company's effort to find new
markets for its clinical products in less developed geographical areas.

Gross profit: Gross profit for the three months ended March 31, 2001 and 2000
was $4,699,700 and $4,883,100 respectively, representing a gross margin of 54.3%
and 61.2% for three months ended March 31, 2001 and 2000, respectively. The
decrease in GPM% was due to the higher infrastructure cost within the
manufacturing area including the higher cost of the new Camarillo facility,
increased depreciation expense, a reduction in WIP inventory in our custom
peptides, antibodies and signal transduction product lines due to improvements
in our production process, increased raw material cost in our serum and media
lines and increased farm cost for antibody production.

                                       10


Research and development: Research and development expense for the three months
ended March 31, 2001 and 2000 amounted to $953,500 and $822,400, respectively.
As a percentage of net sales, research and development expenditures were 11.0%
and 10.4% of net sales for the quarters ended March 31, 2001 and 2000
respectively.

Sales and marketing: Sales and marketing expense for the three months ended
March 31, 2001 and 2000 amounted to $1,922,200 and $1,346,400 respectively. As a
percentage of net sales, sales and marketing expenditures were 22.2% and 17.0%
of net sales for the quarter ended March 31, 2001 and 2000 respectively. The
increased sales and marketing expense of $575,800 represents the Company's
investment in its infrastructure through increased personnel and increased
marketing programs.

General and administrative: General and administrative expense for the three
months ended March 31, 2001 and 2000 amounted to $1,807,200 and $1,092,200
respectively, an increase of $715,000. Included in the increase are (i) a
quarterly non-cash stock compensation charge of $339,000 which began in
September 2000 and will continue through August 2005; (ii) $156,000 related to
the transition costs of the new Senior Management team and legal fees related to
an employee termination suit; and $220,000 related to the Company's investment
in its infrastructure.

Amortization of intangible assets: Amortization of intangible assets for the
three months ended March 31, 2001 and 2000 amounted to $274,600 and $269,400,
respectively and is related to the amortization of the intangible assets from
the QCB and Biofluids acquisitions.

Interest income (expense), net: Net interest income for the three months ended
March 31, 2001 was $136,500 which was related to interest income on cash
invested in short-term securities during the quarter. Net interest expense was
$182,400 for the three months ended March 31, 2000. Interest expense on the
loans associated with the acquisitions of QCB and Bioluids in December 1998 of
$223,000 was offset by $40,600 of interest income from cash invested in short
term investments.

Income tax expense (benefit): The income tax benefit for the three months ended
March 31, 2001 was $22,300 and the provision for income tax expense was $352,200
for the three months ended March 31, 2000. This represent the normalized tax
rate of 31% for the three months ended March 31, 2001 and 2000 respectively.

Liquidity and Capital Resources:

    Cash and cash equivalents as of March 31, 2001 of $9,457,100 decreased by
$1,175,500 from $10,632,600 at December 31, 2000. The decrease in cash was due
in part to a reduction of accounts payable from the end of the year of
$1,007,700. Working capital, which is the excess of current assets over current
liabilities was $20,905,300 at March 31, 2001 as compared to $20,102,100 at
December 31, 2000 representing an increase of $803,200 principally due to the
decrease in accounts payable and accrued expenses.

    In the three months ended March 31, 2001, the Company received $200,500 from
the issuance of common stock related to the exercise of stock options.

    The Company has never paid dividends on common stock and has no plans to do
so in fiscal 2001. Our earnings will be retained for reinvestment in the
business.

    The Company expects to be able to meet our future cash and working capital
requirements for operations and capital additions through currently available
funds and cash generated from operations, if any. However, we may raise
additional capital or secure debt financing from time to time to take advantage
of favorable conditions in the market or in connection with our corporate
development activities.

                                       11


                                 RISK FACTORS

     You should carefully consider the following risk factors and all other
information contained in this report before purchasing shares of our common
stock. Investing in our common stock involves a high degree of risk. If any of
the following events or outcomes actually occur, our business, operating results
and financial condition would likely suffer. As a result, the trading price of
our common stock could decline, and you may lose all or part of the money you
paid to purchase our common stock.

                         Risks Related to Our Business

Failure to manage our growth and expansion could impair our business.

     We historically have sought, and will continue to seek, to increase our
sales and profitability primarily through the acquisition or internal
development of new product lines, additional customers and new businesses. Our
historical revenue growth is primarily attributable to our acquisitions and new
product development and, to a lesser extent, to increased revenues from our
existing products. We expect that future acquisitions, if successfully
consummated, will create increased working capital requirements, which will
likely precede by several months any material contribution of an acquisition to
our net income. Our ability to achieve our expansion objectives and to manage
our growth effectively and profitably depends upon a variety of factors,
including:

 .    our ability to internally develop new products;

 .    our ability to make profitable acquisitions;

 .    integration of new facilities into existing operations;

 .    hiring, training and retention of qualified personnel;

 .    establishment of new relationships or expansion of existing relationships
     with customers and suppliers; and

 .    availability of capital.

     In addition, the implementation of our growth strategy will place
significant strain on our administrative, operational and financial resources
and increased demands on our financial systems and controls. Our ability to
manage our growth successfully will require us to continue to improve and expand
these resources, systems and controls. If our management is unable to manage
growth effectively, our operating results could be adversely affected. Moreover,
there can be no assurance that our historic rate of growth will continue, that
we will continue to successfully expand or that growth or expansion will result
in profitability.

We cannot guarantee that our future acquisitions will be successful.

     We compete for acquisition and expansion opportunities with companies
which have significantly greater financial and management resources than us.
There can be no assurance that suitable acquisition or investment opportunities
will be identified, that any of these transactions can be consummated, or that,
if acquired, these new businesses can be integrated successfully and profitably
into our operations. These acquisitions and investments may also require a
significant allocation of resources, which will reduce our ability to focus on
the other portions of our business, including many of the factors listed in the
prior risk factor.

Reduction or delays in research and development budgets and in government
funding may negatively impact our sales.

                                       12


     Our customers include researchers at pharmaceutical and biotechnology
companies, academic institutions and government and private laboratories.
Fluctuations in the research and development budgets of these researchers and
their organizations could have a significant effect on the demand for our
products. Research and development budgets fluctuate due to numerous factors
that are outside our control and are difficult to predict, including changes in
available resources, spending priorities and institutional budgetary policies.
Our business could be seriously damaged by any significant decrease in life
sciences research and development expenditures by pharmaceutical and
biotechnology companies, academic institutions or government and private
laboratories.

     A significant portion of our sales has been to researchers, universities,
government laboratories and private foundations whose funding is dependent upon
grants from government agencies such as the U.S. National Institutes of Health
and similar domestic and international agencies. Although the level of research
funding has increased during the past several years, we cannot assure that this
trend will continue. Government funding of research and development is subject
to the political process, which is inherently fluid and unpredictable. Our
revenues may be adversely affected if our customers delay purchases as a result
of uncertainties surrounding the approval of government budget proposals. Also,
government proposals to reduce or eliminate budgetary deficits have sometimes
included reduced allocations to the NIH and other government agencies that fund
research and development activities. A reduction in government funding for the
NIH or other government research agencies could seriously damage our business.

     Many of our customers receive funds from approved grants at particular
times of the year, as determined by the federal government. Grants have, in the
past, been frozen for extended periods or have otherwise become unavailable to
various institutions without advance notice. The timing of the receipt of grant
funds affects the timing of purchase decisions by our customers and, as a
result, can cause fluctuations in our sales and operating results.

We rely on raw materials and specialized equipment for our manufacturing, which
we may not always be able to obtain on favorable terms.

     Our manufacturing process relies on the continued availability of
high-quality raw materials and specialized equipment. It is possible that a
change in vendors, or in the quality of the raw materials supplied to us, could
have an adverse impact on our manufacturing process and, ultimately, on the sale
of our finished products. We have from time to time experienced a disruption in
the quality or availability of key raw materials, which has created minor delays
in our ability to fill orders for specific test kits. This could occur again in
the future, resulting in significant delays, and could have a detrimental impact
on the sale of our products and our results of operations. In addition, we rely
on highly specialized manufacturing equipment that if damaged or disabled could
adversely affect our ability to manufacture our products and therefore
negatively impact our business.

Our ability to raise the capital necessary to expand our business is uncertain.

     In the future, in order to expand our business through internal development
or acquisitions, we may need to raise substantial additional funds through
equity or debt financings, research and development financings or collaborative
relationships. However, this additional funding may not be available or, if
available, it may not be available on economically reasonable terms. In
addition, any additional funding may result in significant dilution to existing
stockholders. If adequate funds are not available, we may be required to curtail
our operations or obtain funds through collaborative partners that may require
us to release material rights to our products.

Our research and development efforts for new products may be unsuccessful.

     We incur significant research and development expenses to develop new
products and technologies. There can be no assurance that any of these products
or technologies will be successfully developed or that if developed, will be
commercially successful. In the event that we are unable to develop
commercialized

                                       13


products from our research and development efforts or we are unable or unwilling
to allocate amounts beyond our currently anticipated research and development
investment, we could lose our entire investment in these new products and
technologies. Any failure to translate research and development expenditures
into successful new product introductions could have an adverse effect on our
business.

Failure to license new technologies could impair our new product development.

     Our business model of providing products to researchers working on a
variety of genetic projects requires us to develop a wide spectrum of products.
To generate broad product lines it is advantageous to sometimes license
technologies from others rather than depending exclusively on our own employees.
As a result, we believe our ability to license new technologies from third
parties is and will continue to be important to our ability to offer new
products.

     In addition, from time to time we are notified or become aware of patents
held by third parties that are related to technologies we are selling or may
sell in the future. After a review of these patents, we may decide to obtain a
license for these technologies from these third parties or discontinue the
products. There can be no assurance that we will be able to continue to
successfully identify new technologies developed by others. Even is we are able
to identify new technologies of interest, we may not be able to negotiate a
license on favorable terms, or at all. If we lose the rights to patented
technology, we may need to discontinue selling certain products or redesign our
products, and we may lose a competitive advantage. Potential competitors could
in-license technologies that we fail to license and potentially erode our market
share for certain products. Our licenses typically subject us to various
commercialization, sublicensing, minimum payment, and other obligations. If we
fail to comply with these requirements, we could lose important rights under a
license. In addition, certain rights granted under the license could be lost for
reasons out of our control. For example, the licensor could lose patent
protection for a number of reasons, including invalidity of the licensed patent.
We do not always receive significant indemnification from a licensor against
third party claims of intellectual property infringement.

     We are currently in the process of negotiating several of these licenses
and expect that we will also negotiate these types of licenses in the future.
There can be no assurances that we will be able to negotiate these licenses on
favorable terms, or at all.

Our future success depends on the timely introduction of new products and the
acceptance of these new products in the marketplace.

     Our ability to gain access to technologies needed for new products and
services also depends in part on our ability to convince licensors that we can
successfully commercialize their inventions. We cannot assure that we will be
able to continue to identify new technologies developed by others. Even if we
are able to identify new technologies of interest, we may not be able to
negotiate a license on favorable terms, or at all.

If we fail to introduce new products, or our new products are not accepted by
potential customers, we may lose market share.

     Rapid technological change and frequent new product introductions are
typical for the markets we serve. Our future success will depend in part on
continuous, timely development and introduction of new products that address
evolving market requirements. We believe successful new product introductions
provide a significant competitive advantage because customers make an investment
of time in selecting and learning to use a new product, and then are reluctant
to switch. To the extent we fail to introduce new and innovative products, we
may lose market share to our competitors, which will be difficult or impossible
to regain. Any inability, for technological or other reasons, to successfully
develop and introduce new products could reduce our growth rate or damage our
business.

     In the past we have experienced, and are likely to experience in the
future, delays in the development and introduction of products. We cannot assure
that we will keep pace with the rapid rate of change in life sciences research,
or that our new products will adequately meet the requirements of the
marketplace or achieve market acceptance. Some of the factors affecting market
acceptance of new products include:

                                       14


 .    availability, quality and price relative to competitive products;

 .    the timing of introduction of the product relative to competitive
    products;

 .    customers' opinion of the products utility;

 .    ease of use;

 .    consistency with prior practices;

 .    scientists' opinion of the product's usefulness;

 .    citation of the product in published research; and

 .    general trends in life sciences research.

   The expenses or losses associated with unsuccessful product development
activities or lack of market acceptance of our new products could materially
adversely affect our business, operating results and financial condition.

     The development, introduction and marketing of innovative products in our
rapidly evolving markets will require significant sustained investment. We
cannot assure their cash from operations or other sources will be sufficient to
meet these ongoing requirements.

Failure to attract and retain qualified scientific or production personnel or
loss of key management or key personnel could hurt our business.

     Recruiting and retaining qualified scientific and production personnel to
perform research and development work and product manufacturing is critical to
our success. Because the industry in which we compete is very competitive, we
face significant challenges attracting and retaining this qualified personnel
base. Although we believe we have been and will be able to attract and retain
these personnel, there can be no assurance that we will be able to continue to
successfully attract qualified personnel. In addition, our anticipated growth
and expansion into areas and activities requiring additional expertise, such as
clinical testing, government approvals, production and marketing, will require
the addition of new management personnel and the development of additional
expertise by existing management personnel. The failure to attract and retain
these personnel or, alternatively, to develop this expertise internally would
adversely affect our business. We generally do not enter into employment
agreements requiring these employees to continue in our employment for any
period of time.

     Our success also will continue to depend to a significant extent on the
members of our management team and, in particular, on our Chief Executive
Officer and President, Russell D. Hays. We do not maintain any "key man"
insurance policies regarding any of these individuals. We may not be able to
retain the services of our executive officers and key personnel or attract
additional qualified members to management in the future. The loss of services
of Mr. Hays or of any of our other key management or employees, could have a
material adverse effect upon our business.

Many of our customers are obtaining our products through new distribution
channels and methods that may adversely impact our results of operations and
financial condition.

     A number of our customers have developed purchasing initiatives to reduce
the number of vendors they purchase from in order to lower their supply costs.
In some cases, these customers have established agreements with large
distributors which include discounts and the distributors' direct involvement
with the purchasing process. For similar reasons, many larger customers,
including the federal government, have

                                       15


special pricing arrangements, including blanket purchase agreements. These
agreements may limit our pricing flexibility with respect to our products, which
could adversely impact our business, financial condition and results of
operations. In addition, although we accept and process some orders through our
Internet website, we also implement sales through a third party Internet vendor.
Internet sales through third parties will negatively impact our gross margins
because we pay commission on these Internet sales. On the other hand, if we do
not enter into arrangements with third-party e-commerce providers, we may lose
customers who prefer to purchase products using these Web sites. Our business
may be harmed as a result of these Web sites or other sales methods which may be
developed in the future.

We rely on international sales, which are subject to additional risks.

     International sales accounted for approximately 44.6% of our revenues in
2000 and 43.7% of our revenues for the three months ended March 31, 2001 and
2000, respectively.. International sales can be subject to many inherent risks
that are difficult or impossible for us to predict or control, including:

 .    unexpected changes in regulatory requirements and tariffs;

 .    difficulties and costs associated with in staffing and managing foreign
     operations, including foreign distributor relationships;

 .    longer accounts receivable collection cycles in certain foreign countries;

 .    adverse economic or political changes;

 .    unexpected changes in regulatory requirements;

 .    more limited protection for intellectual property in some countries;

 .    changes in our international distribution network and direct sales force;

 .    potential trade restrictions, exchange controls and import and export
     licensing requirements;

 .    problems in collecting accounts receivable; and

 .    potentially adverse tax consequences of overlapping tax structure.

     We intend to continue to generate revenues from sales outside North America
in the future. Future distribution of our products outside North America also
may be subject to greater governmental regulation. These regulations, which
include requirements for approvals or clearance to market, additional time
required for regulatory review and sanctions imposed for violations, as well as
the other risks indicated in the bullets listed above, vary by country. We may
not be able to obtain regulatory approvals in the countries in which we
currently sell our products or in countries where we may sell our products in
the future. In addition, we may be required to incur significant costs in
obtaining necessary regulatory approvals. Failure to obtain necessary regulatory
approvals or any other failure to comply with regulatory requirements could
result in a material reduction in our revenues and earnings.

     We also depend on third-party distributors for a material portion of our
international sales. If we lose or suffer any significant reduction in sales to
any material distributor, our business could be materially adversely affected.

     In addition, approximately 20.9% of our sales are made in foreign
currencies, primarily Belgian francs, British pounds, and German marks. Although
a significant portion of the foreign currencies in which we conduct our business
is currently, or may in the future be, denominated in Euros as a result of the
European

                                       16


Monetary Union, we are not certain about the effect of the Euro on our business,
financial condition or results of operations. In the past, gains and losses on
the collection of our accounts receivable arising from international operations
have contributed to negative fluctuations in our results of operations. In
general, increases in the exchange rate of the United States dollar to foreign
currencies cause our products to become relatively more expensive to customers
in those countries, leading to a reduction in sales or profitability in some
cases. We historically have not, and currently are not, using hedging
transactions or other means to reduce our exposure to fluctuations in the value
of the United States dollar as compared to the foreign currencies in which many
of our sales are made.

 Our operating results may fluctuate.

     Our operating results may vary significantly quarter to quarter and from
year to year as a result of a variety of factors. These factors include:

 .    level of demand for our products;

 .    changes in our customer and product mix;

 .    timing of acquisitions and investments in infrastructure;

 .    competitive conditions;

 .    timing and extent of intellectual property litigation;

 .    exchange rate fluctuations; and

 .    general economic conditions.

     We believe that quarterly comparisons of our financial results may not
necessarily be meaningful and should not be relied upon as an indication of
future performance. Additionally, if our operating results in one or more
quarters do not meet the expectations of security analysts or others, the price
of our common stock could be materially adversely affected.

     Our continued investment in product development and sales and marketing are
significantly ongoing expenses. If revenue in a particular period falls short of
expectations, we may not be able to reduce significantly our expenditures for
that period, which would materially adversely affect the operating results for
that period.

We may be unable to protect our trademarks, trade secrets and other intellectual
property rights that are important to our business.

     We regard our trademarks, trade secrets and other intellectual property as
a component of our success. We rely on trademark law and trade secret protection
and confidentiality and/or license agreements with employees, customers,
partners and others to protect our intellectual property. Effective trademark
and trade secret protection may not be available in every country in which our
products are available. We cannot be certain that we have taken adequate steps
to protect our intellectual property, especially in countries where the laws may
not protect our rights as fully as in the United States. In addition, our
third-party confidentiality agreements can be breached and, if they are, there
may not be an adequate remedy available to us. If our trade secrets become
known, we may lose our competitive position.

Intellectual property or other litigation could harm our business.

                                       17


     Litigation regarding patents and other intellectual property rights is
extensive in the biotechnology industry. We are aware that patents have been
applied for, and in some cases issued to others, claiming technologies that are
closely related to ours. As a result, and in part due to the ambiguities and
evolving nature of intellectual property law, we periodically receive notices of
potential infringement of patents held by others. Although to date we have
successfully resolved these types of claims, we may not be able to do so in the
future.

     In the event of an intellectual property dispute, we may be forced to
litigate. This litigation could involve proceedings declared by the U.S. Patent
and Trademark Office or the International Trade Commission, as well as
proceedings brought directly by affected third parties. Intellectual property
litigation can be extremely expensive, and these expenses, as well as the
consequences should we not prevail, could seriously harm our business.

     If a third party claimed an intellectual property right to technology we
use, we might need to discontinue an important product or product line, alter
our products and processes, pay license fees or cease our affected business
activities. Although we might under these circumstances attempt to obtain a
license to this intellectual property, we may not be able to do so on favorable
terms, or at all.

     In addition to intellectual property litigation, other substantial, complex
or extended litigation could result in large expenditures by us and distraction
of our management. For example, lawsuits by employees, stockholders,
collaborators or distributors could be very costly and substantially disrupt our
business. Disputes from time to time with companies or individuals are not
uncommon in our industry, and we cannot assure you that we will always be able
to resolve them out of court.

Accidents related to hazardous materials could adversely affect our business.

     Portions of our operations require the controlled use of hazardous and
radioactive materials. Although we believe our safety procedures comply with the
standards prescribed by federal, state, local and foreign regulations, the risk
of accidental contamination of property or injury to individuals from these
materials cannot be completely eliminated. In the event of an accident, we could
be liable for any damages that result, which could seriously damage our business
and results of operations.

Our sales are subject to seasonality, which means that we have less revenue in
some months.

     We experience a slowing of sales in Europe during the summer months and
worldwide during the Christmas holidays. Generally, our fourth quarter revenues
are lower than our revenues in each of the first three quarters of the year. We
believe that period to period comparisons of our operating results may not
necessarily be reliable indicators of our future performance. It is likely that
in some future period our operating results will not meet expectations or those
of public market analysts, which could result in reductions in the market price
of our common stock.

Potential product liability claims could affect our earnings and financial
condition.

     We face a potential risk of liability claims based on our products and
services, and we have faced such claims in the past. We carry product liability
insurance coverage which is limited in scope and amount but which we believe to
be adequate. We cannot assure you, however, that we will be able to maintain
this insurance at reasonable cost and on reasonable terms. We also cannot assure
that this insurance will be adequate to protect us against a product liability
claim, should one arise.

The labor laws applicable to our employees in Europe may restrict the
flexibility of our management.

     As of April 30, 2001, 58 of our 232 employees worked for our BioSource
Europe subsidiary, which is located in Nivelles, Belgium. As a result of Belgian
labor laws, we are required to make specified severance payments in the event we
terminate a European employee. Accordingly, our management may be limited by the
application of the Belgian labor laws in the determination of staffing levels,
and may have

                                       18


less flexibility in making such determinations than our competitors whose
employees are not subject to similar labor laws.

                      Risks Associated With Our Industry

The biomedical research products industry is very competitive, and we may be
unable to continue to compete effectively in this industry in the future.

     We are engaged in a segment of the biomedical research products industry
that is highly competitive. We compete with many other suppliers and new
competitors continue to enter the markets. Many of our competitors, both in the
United States and elsewhere, are major pharmaceutical, chemical and
biotechnology companies, and many of them have substantially greater capital
resources, marketing experience, research and development staffs, and facilities
than we do. Any of these companies could succeed in developing products that are
more effective than the products that we have or may develop and may also be
more successful than us in producing and marketing their products. We expect
this competition to continue and intensify in the future. Competition in our
markets is primarily driven by:

 .    product performance, features and liability;

 .    price;

 .    timing of product introductions;

 .    ability to develop, maintain and protect proprietary products and
     technologies;

 .    sales and distribution capabilities;

 .    technical support and service;

 .    brand royalty;

 .    applications support; and

 .    breadth of product line.

     If a competitor develops superior technology or cost-effective alternatives
to our products, our business, financial condition and results of operations
could be materially adversely affected.

     Our competitors have in the past and may in the future compete by lowering
prices. We may respond by lowering our prices, which could reduce revenues and
profits. Conversely, failure to anticipate and respond to price competition may
damage our market share.

     Our industry has also seen substantial consolidation in recent years,
which has led to the creation of competitors with greater financial and
intellectual property resources than us. In addition, we believe that the
success that others have had in our industry will attract new competitors. Some
of our current and future competitors also may cooperate to better compete
against us. We may not be able to compete effectively against these current or
future competitors. Increased competition could result in price reductions for
our products, reduced margins and loss of market share, any of which could
adversely impact our business, financial condition and results of operations.

As a result of consolidation in the pharmaceutical industry, we may lose
existing customers or have greater difficulty obtaining new customers.

     In recent years, the United States pharmaceutical industry has undergone
substantial consolidation. As part of many business combinations, companies
frequently reduce the number of suppliers used and we

                                       19


may not be selected as a supplier after any business combination.  Further,
mergers or corporate consolidations in the pharmaceutical industry could cause
us to lose existing customers and potential future customers, which could have a
material adverse effect on our business, financial condition and results of
operations.

We are currently subject to government regulation.

     Our business is currently subject to regulation, supervision and licensing
by federal, state and local governmental authorities. Also, from time to time we
must expend resources to comply with newly adopted regulations, as well as
changes in existing regulations. If we fail to comply with these regulations, we
could be subject to disciplinary actions or administrative enforcement actions.
These actions could result in penalties, including fines.

                    Risks Associated With Our Common Stock

Our stock price has been volatile.

     Our common stock is quoted on the Nasdaq National Market, and there has
been substantial volatility in the market price of our common stock. The trading
price of our common stock has been, and is likely to continue to be, subject to
significant fluctuations due to a variety of factors, including:

 .    fluctuations in our quarterly operating and earnings per share results;

 .    the gain or loss of significant contracts;

 .    loss of key personnel;

 .    announcements of technological innovations or new products by us or our
     competitors;

 .    delays in the development and introduction of new products;

 .    legislative or regulatory changes;

 .    general trends in the industry;

 .    recommendations and/or changes in estimates by equity and market research
     analysts;

 .    biological or medical discoveries;

 .    disputes and/or developments concerning intellectual property, including
     patents and litigation matters;

 .    public concern as to the safety of new technologies;

 .    sales of common stock of existing holders;

 .    securities class action or other litigation; and

 .    developments in our relationships with current or future customers and
     suppliers; and

 .    general economic conditions, both in the United States and abroad.

                                       20


     As a result of these factors, and potentially others, the sales price of
our common stock has ranged from $2.41 to $32.00 per share from January 1, 1998
through April 30, 2001 and from $6.00 to $13.69 per share from January 1, 2001
through April 30, 2001.

     In addition, the stock market in general has experienced extreme price and
volume fluctuations that have affected the market price of our common stock, as
well as the stock of many biotechnology companies. Often, price fluctuations are
unrelated to operating performance of the specific companies whose stock is
affected.

     In the past, following periods of volatility in the market price of a
company's stock, securities class action litigation has occurred against the
issuing company. If we were subject to this type of litigation in the future, we
could incur substantial costs and a diversion of our management's attention and
resources, each of which could have a material adverse effect on our revenue and
earnings. Any adverse determination in this type of litigation could also
subject us to significant liabilities.

Anti-takeover provisions in our governing documents and under applicable law
could impair the ability of a third party to take over our company.

   We are subject to various legal and contractual provisions that may impede a
change in our control, including the following:

 .    our adoption of a stockholders' rights plan, which could result in the
     significant dilution of the proportionate ownership of any person that
     engages in an unsolicited attempt to take over our company; and

 .    the ability of our board of directors to issue additional shares of our
     preferred stock, which shares may be given superior voting, liquidation,
     distribution and other rights as compared to our common stock.

     These provisions, as well as other provisions in our certificate of
incorporation and bylaws and under the Delaware General Corporations Law, may
make it more difficult for a third party to acquire our company, even if the
acquisition attempt was at a premium over the market value of our common stock
at that time.

     Our principal stockholders and management own a significant percentage of
our capital stock and will be able to exercise significant influence over our
affairs. Our executive officers, directors and principal stockholders will
continue to beneficially own 30.7% of our outstanding common stock, based upon
the beneficial ownership of our common stock as of March 20, 2001. In addition,
these same persons also hold options to acquire additional shares of our common
stock, which may increase their percentage ownership of the common stock further
in the future. Accordingly, these stockholders:

 .    will be able to significantly influence the composition of our board of
 directors;

 .    will significantly influence all matters requiring stockholder approval,
 including change of control transactions; and

 .    will continue to have significant influence over our business.

     This concentration of ownership of our common stock could have the effect
of delaying or preventing a change of control of us or otherwise discouraging a
potential acquirer from attempting to obtain control of us. This in turn could
have a negative effect on the market price of our common stock. It could also
prevent our stockholders from realizing a premium over the market prices for
their shares of common stock.

Our principal stockholders and management own a significant percentage of our
capital stock and will be able to exercise significant influence over our
affairs.

                                       21


     Our executive officers, directors and principal stockholders beneficially
own approximately 30.6% of our outstanding common stock, based upon the
beneficial ownership of our common stock as of March 20, 2001. As a result,
these stockholders, if they act together, could exert substantial influence over
matters requiring stockholder approval, including the election of directors and
approval of mergers and other significant corporate transactions. The voting
power of such persons may have the effect of delaying, preventing or deterring a
change in control, and could affect the market price of our common stock.

Absence of dividends could reduce our attractiveness to you.

     Some investors favor companies that pay dividends, particularly in general
downturns in the stock market. We have never declared or paid any cash dividends
on our common stock. We currently intend to retain any future earnings for
funding growth and we do not currently anticipate paying cash dividends on our
common stock in the foreseeable future. Because we may not pay dividends, the
return on this investment likely depends on selling this stock at a profit.

Item 3. Quantitative and Qualitative Disclosures of Market Risk:

     We conduct business in various foreign currencies and are therefore subject
to the transaction exposures that arise from foreign exchange rate movements
between the dates that foreign currency transactions are initiated and the date
that they are converted. We are also subject to certain exposures arising from
the translation and consolidation of the financial results of our foreign
subsidiaries. There can be no assurance that actions taken to manage such
exposures will continue to be successful or that future changes in currency
exchange rates will not have a material impact on our future cash collections
and operating results. We do not currently hedge either our transaction risk or
our economic risk.

                                       22


                                    Part II

                               Other Information

Item 1.  Legal Proceedings

         On June 14, 2000, one of our former employees, Jordan Fishman, Ph.D.,
filed a legal action against us in the United States Central District Court of
California. Mr. Fishman's complaint asserts a number of claims for relief
against BioSource and alleges that BioSource breached Mr. Fishman's employment
agreement by failing to register his stock options on a Form S-8 Registration
Statement by December 8, 1999. Second, Fishman claims that this breach, coupled
with BioSource's representations regarding a planned public offering (which
prevented Company insiders from trading in the Company's common stock) and
BioSource's subsequent termination of Fishman's employment, were each part of a
larger scheme to interfere with, and ultimately prevent, the sale of his common
stock. On August 11, 2000, we filed a motion to dismiss five of Mr. Fishman's
six causes of action, and on September 29, 2000, the court dismissed three of
the causes. On October 4, 2000, Mr. Fishman filed a first amended complaint.
BioSource moved to dismiss two of the remaining causes of action, one based on
new California Supreme Court precedent, and the other based on deficiencies in
Mr. Fishman's allegations. The Court granted BioSource's motion as to both of
these causes of action. As a consequence, the only two remaining causes of
action in this litigation are (1) breach of contract and (2) fraud. On October
23, 2000, counsel for Fishman and BioSource conducted their Early Meeting of
Counsel where they exchanged documents and agreed upon discovery and motion
cut-off dates, trial estimates, and exchanged initial witness lists. In December
2000, BioSource answered the First Amended Complaint, and filed a counter-claim
against Jordan Fishman. The parties are conducting depositions and other
discovery. The case is scheduled for trial commencing July 17, 2001. No
substantive adjudication of Mr. Fishman's claims has yet occurred, however, the
Company believes that it has substantial defenses to Fishman's remaining causes
of action.

     The Company has also commenced an arbitration proceeding against the former
shareholders of its QCB division, including Mr. Fishman, to recover damages
management believes it has suffered in connection with misrepresentations and
omissions made by those shareholders in the representations and warranties
contained in the original Stock Purchase Agreement for QCB executed on December
9, 1998. The Company's claim to recover the $1,347,000 of Escrowed Funds is
based on QCB's breach of the representations and warranties made in the Stock
Purchase Agreement. The parties have selected a panel of three arbitrators who
will hear the dispute in November, 2001. The Company has also asserted a claim
for punitive damages against Jordan Fishman in the arbitration.

Item 2.  Change in Securities and Use of Proceeds

         None

Item 3.  Defaults Upon Senior Securities
         None.

Item 4.  Submission of matters to a vote of security holders.
         None.

Item 5.  Other Information
         None.

Item 6.  Exhibits and Reports on Form 8-K

         (a)   Exhibits
                    None

         (b)   Reports on Form 8-K
                      Current Report on Form 8-K dated February 28, 2001,
                      reporting Items 5 and 7 and filed with the Securities and
                      Exchange Commission on March 22, 2001.

                                       23


                                  SIGNATURES

               Pursuant to the requirements of the Securities Exchange Act of
1934, as amended, the registrant has duly caused this report to be signed on its
behalf by the undersigned thereunto duly authorized.

                                        BIOSOURCE INTERNATIONAL, INC.
                                                  (Registrant)




Date: May 11, 2001                       /s/      RUSSELL D. HAYS
                                                  ---------------
                                                  Russell D. Hays
                                                  Chairman of the Board,
                                                  President and Chief
                                                  Executive Officer

Date: May 11, 2001                       /s/      CHARLES C. BEST
                                                  ---------------
                                                  Charles C. Best
                                                  Executive Vice President and
                                                  Chief Financial Officer

                                       24