Exhibit 10.8


                               OPTION CERTIFICATE
                          (NON-STATUTORY STOCK OPTION)

     THIS IS TO CERTIFY that BioSource International, Inc., a Delaware
corporation (the "Company"), has granted to the person named below a
non-statutory stock option (the "Option") to purchase shares of the Company's
Common Stock, par value $0.001 per share (the "Shares"), as follows:

Name of Optionee:       Jordan B. Fishman, Ph.D.

Address of Optionee:    29 Lynbrook Road
                        Southborough, Massachusetts 01772

Number of Shares:       100,000

Option Exercise Price:  $2 13/16

Option Expiration Date: December 8, 2008

     EXERCISE SCHEDULE: The Option shall become exercisable as follows: the
option to purchase 33,333 shares vests on December 9, 1999, the option to
purchase an additional 33,333 shares vests on December 9, 2000 and the option to
purchase an additional 33,334 shares vests on December 9, 2001 (the "Vesting
Date").

     SUMMARY OF OTHER TERMS: This Option is defined in the Stock Option
Agreement (Non-Statutory Stock Option) (the "Option Agreement") which is
attached to this Option Certificate (the "Certificate") as Annex I. This
Certificate summarizes certain of the provisions of the Option Agreement for
your information, but is not complete. Your rights are governed by the Option
Agreement, not by this Summary. The Company strongly suggests that you carefully
review the full Option Agreement prior to signing this Certificate or exercising
the Option.

     Among the terms of the Option Agreement are the following:

     EMPLOYMENT: Unless otherwise provided in your Executive Employment
Agreement with the Company, dated as of December 9, 1998 ("Employment
Agreement"), the Option Agreement obligates you to work for the Company (or hold
office if you are a director) for one (1) year from the Date of Grant of the
Option. Note, however, that should you fail to do so, the Company's sole remedy
is to cancel the portion of your Option which is not then


<PAGE>


exercisable (unless otherwise provided in your Employment Agreement). The Option
Agreement does not obligate the Company to retain you for one (1) year. See
Paragraph 3 and the Exercise Schedule, above. Unless otherwise agreed in
writing, the Company reserves the right to terminate any employee at any time,
with or without cause.

     TERMINATION OF EMPLOYMENT: Unless otherwise provided in your Employment
Agreement, while the Option terminates on the Option Expiration Date, it will
terminate earlier if you cease to be employed by the Company (or hold office if
you are a director). If your employment is terminated "for cause" (as defined in
your Employment Agreement), the Option terminates 30 days after the date of
termination of employment, and is exercisable during such 30 day period as to
the portion of the Option which had vested prior to the date of termination of
employment. If your employment is terminated due to death or permanent
disability, the Option terminates one year after the date of death or
disability, and is exercisable during such one year period as to the portion of
the Option which had vested prior to the date of death or disability. Unless
otherwise provided in your Employment Agreement, in all other cases, the Option
terminates 90 days after the date of termination of employment, and is
exercisable during such 90 day period as to the portion of the Option which had
vested prior to the date of termination of employment. See Paragraph 5.

     TRANSFER: The Option is personal to you, and cannot be sold, transferred,
assigned or otherwise disposed of to any other person, except on your death. See
Paragraph 15(d).

     EXERCISE: You can exercise the Option (once it is exercisable), in whole or
in part, by delivering to the Company a Notice of Exercise identical to Exhibit
"A" attached to the Option Agreement, accompanied by payment of the Exercise
Price for the Shares to be purchased. The Company will then issue a certificate
to you for the Shares you have purchased. You are under no obligation to
exercise the Option. See Paragraph 4.

     ANTI-DILUTION PROVISIONS: The Option contains provisions which adjust your
Option to reflect stock splits, stock dividends, mergers and other major
corporate reorganizations which would change the nature of the Shares underlying
your Option. See Paragraph 7.

     WAIVER: By signing this Certificate, you will be agreeing to all of the
terms of the Option Agreement, including those not summarized in this
Certificate. You will waive your rights to options or stock which may have been
promised to you. See Paragraph 8.

     WITHHOLDING: The Company may require you to make any arrangements necessary
to insure the proper withholding of any amount of tax, if any, required to be
withheld by the Company as a result of the exercise of the Option. See Paragraph
13.


                                  EX-10-8 - 2
<PAGE>


                                    AGREEMENT

     BioSource International, Inc., a Delaware corporation (the "Company"), and
the above-named person (the "Optionee") each hereby agrees to be bound by all of
the terms and conditions of the Stock Option Agreement (Incentive Stock Option)
which is attached hereto as Annex I and incorporated herein by this reference if
set forth in full in this document.

DATED: December 9, 1998

                                       BIOSOURCE INTERNATIONAL, INC.


                                       BY:   /S/ JAMES CHAMBERLAIN
                                             -----------------------------------
                                             Its:  President & Chief Executive
                                                   Officer


                                       BY:  /S/ JORDAN S. FISHMAN
                                             -----------------------------------
                                             Employee Signature

                                              -------------------------------
                                              (Please print your name exactly
                                              as you wish it to appear on any
                                             stock certificates issued to you
                                               upon exercise of the Option)


                                  EX-10-8 - 3
<PAGE>


                                     ANNEX I

                             STOCK OPTION AGREEMENT
                          (Non-Statutory Stock Option)

     This STOCK OPTION AGREEMENT (this "Option Agreement") is made and entered
into on the execution date of the Option Certificate to which it is attached
(the "Certificate"), by and between BioSource International, Inc., a Delaware
corporation (the "Company"), and the person named in the Certificate
("Optionee").

     The Board of Directors of the Company (the "Board") has authorized the
grant to Optionee of a non-statutory stock option to purchase shares of the
Company's Common Stock, par value $0.001 per share (the "Common Stock"), upon
the terms and subject to the conditions set forth in this Option Agreement.

     The Company and Optionee agree as follows:

     1. Grant of Option.

          The Company hereby grants to Optionee the right and option (the
     "Option"), upon the terms and subject to the conditions set forth in this
     Option Agreement, to purchase all or any portion of that number of shares
     of the Common Stock (the "Shares") set forth in the Certificate, at the
     Option exercise price set forth in the Certificate (the "Exercise Price").

     2. Term of Option.

     The Option shall terminate and expire on the Option Expiration Date set
forth in the Certificate, unless sooner terminated as provided herein.

     3. Exercise Period.

          (a) Subject to the provisions of Paragraphs 3(b), 5, 7(c) and 7(d) of
     this Option Agreement and except as otherwise provided in your Executive
     Employment Agreement with the Company (the "Employment Agreement"), the
     Option shall become exercisable (in whole or in part) upon and after the
     dates set forth under the caption "Exercise Schedule" in the Certificate.
     The installments shall be cumulative; i.e., the Option may be exercised, as
     to any or all Shares covered by an installment, at any time or times after
     the installment first becomes exercisable and until expiration or
     termination of the Option.


                                  EX-10-8 - 4
<PAGE>


          (b) Notwithstanding anything to the contrary contained in this Option
     Agreement, the Option may not be exercised, in whole or in part, unless and
     until any then-applicable requirements of all federal, state and local laws
     and regulatory agencies shall have been fully complied with to the
     satisfaction of the Company and its counsel.

     4. Exercise of Option.

          There is no obligation to exercise the Option, in whole or in part.
     The Option may be exercised, in whole or in part, only by delivery to the
     Company of:

          (a) written notice of exercise in form and substance identical to
     Exhibit "A" attached to this Option Agreement stating the number of shares
     of Common Stock then being purchased (the "Purchased Shares"); and

          (b) payment of the Exercise Price of the Purchased Shares, either in
     cash, by check, by cancellation of any indebtedness of the Company to
     Optionee for accrued and unpaid salary or, with the consent of the Board
     (or a committee thereof), by transfer to the Company of issued and
     outstanding shares of Common Stock which have been held by Optionee for a
     period of at least six calendar months preceding the date of surrender and
     which have a fair market value equal to the exercise price, or by any
     combination of the above methods of payment. If payment is made, in whole
     or in part, by transfer to the Company of issued and outstanding shares of
     Common Stock, the value of such shares shall be determined as follows: (i)
     if the Stock is listed on an exchange or exchanges, or admitted for trading
     in a market system which provides last sale data under Rule l lAa3-1 of the
     General Rules and Regulations of the Securities and Exchange Commission
     under the Securities and Exchange Act of 1934, as amended (a "Market
     System"), the last reported sales price per share on the last business day
     prior to such date on the principal exchange on which it is traded, or in
     such a Market System, as applicable, or if no sale was made on such day on
     such principal exchange or in such a Market System, as applicable, the last
     reported sales price per share on the most recent day prior to such date on
     which a sale was reported on such exchange or such Market System, as
     applicable; or (ii) if the Common Stock is not then traded on an exchange
     or in such a Market System, the average of the closing bid and asked prices
     per share for the Common Stock in the over-the-counter market as quoted on
     NASDAQ on the day prior to such date; or (iii) if the Common Stock is not
     listed on an exchange or quoted on NASDAQ, an amount determined in good
     faith by the Board (or a committee thereof).

     Following receipt of the notice and payment referred to above, the Company
shall issue and deliver to Optionee a stock certificate or stock certificates
evidencing the


                                  EX-10-8 - 5
<PAGE>


Purchased Shares; provided, however, that the Company shall not be obligated to
issue a fraction or fractions of a share of its Common Stock, and may pay to
Optionee, in cash or by check, the fair market value of any fraction or
fractions of a share exercised by Optionee, which fair market value shall be
determined as set forth in the preceding paragraph.

     5.   Termination of Employment.

          (a) Unless otherwise provided in your Employment Agreement, if
     Optionee shall cease to be a Director of the Company, or to be in the
     employ of, or a consultant to the Company, any Subsidiary or any Parent for
     any reason other than Optionee's death, permanent disability, or
     retirement, Optionee shall have the right to exercise the Option at any
     time within 90 days after the date Optionee ceased to be a Director of the
     Company, or to be employed by, or to be a consultant to the Company, and
     prior to the date of termination of the Option under Paragraph 2 of this
     Option Agreement with respect to all shares with respect to which the
     Option was exercisable at the date Optionee's employment terminated as to
     which the Option had not previously been exercised; and, unless otherwise
     provided in your Employment Agreement, to the extent unexercised at the end
     of this period, the Option shall terminate. Unless otherwise provided in
     your Employment Agreement, the Board (or a committee thereof), in its sole
     and absolute discretion, shall determine whether or not authorized leaves
     of absence shall constitute termination of employment for purposes of this
     Option Agreement.

          (b) If Optionee shall be terminated "for cause" by the Company, any
     Subsidiary or any Parent, Optionee shall have the right to exercise the
     Option at any time within 30 days after such termination of employment and
     prior to the date of termination of the Option under Paragraph 2 of this
     Option Agreement with respect to all Shares with respect to which the
     Option was exercisable on the effective date his employment terminated as
     to which the Option had not previously been exercised.

          (c) Unless otherwise provided in your Employment Agreement, if
     Optionee shall cease to be a Director of the Company, or to be in the
     employ of, or a consultant to the Company, any Subsidiary or any Parent by
     reason of Optionee's death, permanent disability, or retirement (a "Special
     Terminating Event"), then Optionee, Optionee's executors or administrators
     or any person or persons acquiring the Option directly from Optionee by
     bequest or inheritance, shall have the right to exercise the Option with
     respect to all Shares granted under the Option at any time within one year
     after such Special Terminating Event; to the extent the Option is
     unexercised at the end of that period, the Option will terminate.


                                  EX-10-8 - 6
<PAGE>


          (d) For purposes of this Option Agreement, unless otherwise defined in
     your Employment Agreement, a termination "for cause" shall mean termination
     by the Company by reason of:

               (1) with respect to employees of the Company:

                    (i) the failure or refusal by Optionee to perform his duties
               to the Company; or

                    (ii) Optionee's willful disobedience of any orders or
               directives of the Board or any officers thereof acting under the
               authority thereof or Optionee's deliberate interference with the
               compliance by other employees of the Company with any such orders
               or directives; or

                    (iii) the failure or refusal of Optionee to abide by or
               comply with the written policies, standard procedures or
               regulations of the Company; or

                    (iv) any willful or continued act or course of conduct by
               Optionee which the Board in good faith determines might
               reasonably be expected to have a material detrimental effect on
               the Company or the business, operations, affairs or financial
               position thereof; or

                    (v) the committing by the Optionee of any fraud, theft,
               embezzlement or other dishonest act against the Company; or

                    (vi) the determination by the Board, in good faith and in
               the exercise of reasonable discretion, that Optionee is not
               competent to perform his duties of employment; and

               (2) with respect to consultants, any material breach of their
          consulting agreement with the Company.

          (e) For purposes of this Option Agreement, "permanent disability"
     shall have the meaning set forth in Section 2(a)(iii) of your Employment
     Agreement.

     6. Restrictions on Purchased Shares.

          None of the Purchased Shares shall be transferred (with or without
     consideration), sold, offered for sale, assigned, pledged, hypothecated or
     otherwise disposed of (each a "Transfer") and the Company shall not be
     required to register any such Transfer and the Company may instruct its
     transfer agent not to register any such Transfer, unless and until all of
     the following events shall have occurred:


                                  EX-10-8 - 7
<PAGE>


          (a) the Purchased Shares are Transferred pursuant to and in conformity
     with (i) (x) an effective registration statement filed with the Securities
     and Exchange Commission (the "Commission") pursuant to the Securities Act
     of 1933, as amended (the "Act"), or (y) an exemption from registration
     under the Act; and (ii) the securities laws of any state of the United
     States; and

          (b) Optionee has, prior to the Transfer of such Purchased Shares,
     provided all relevant information to Company's counsel so that upon
     Company's request, Company's counsel is able to, and actually prepares and
     delivers to the Company a written opinion that the proposed Transfer (i)
     (x) is pursuant to a registration statement which has been filed with the
     Commission and is then effective, or (y) is exempt from registration under
     the Act as then in effect, and the Rules and Regulations of the Commission
     thereunder; and (ii) is either qualified or registered under any applicable
     state securities laws, or exempt from such qualification or registration.
     The Company shall bear all reasonable costs of preparing such opinion.

          Any attempted Transfer which is not in full compliance with this
     Paragraph 6 shall be null and void ab initio, and of no force or effect.

     7. Adjustments upon Recapitalization.

          Subject to any required action by the shareholders of the Company:

          (a) If the outstanding shares of the Common Stock shall be subdivided
     into a greater number of shares of the Common Stock, or a dividend in
     shares of Common Stock or other securities of the Company convertible into
     or exchangeable for shares of the Common Stock (in which latter event the
     number of shares of Common Stock issuable upon the conversion or exchange
     of such securities shall be deemed to have been distributed) shall be paid
     in respect of the shares of Common Stock, the Exercise Price in effect
     immediately prior to such subdivision or at the record date of such
     dividend shall, simultaneously with the effectiveness of such subdivision
     or immediately after the record date of such dividend, be proportionately
     reduced, and conversely, if the outstanding shares of Common Stock shall be
     combined into a smaller number of shares of Common Stock, the Exercise
     Price in effect immediately prior to such combination shall, simultaneously
     with the effectiveness of such combination, be proportionately increased.

          (b) When any adjustment is required to be made in the Exercise Price,
     the number of Shares purchasable upon the exercise of the Option shall be
     adjusted to that number of Shares determined by (i) multiplying an amount
     equal to the number of Shares purchasable on the exercise of the Option
     immediately prior to such adjustment by the Exercise Price in effect
     immediately prior to such adjustment,


                                  EX-10-8 - 8
<PAGE>


     and then (ii) dividing that product by the Exercise Price in effect
     immediately after such adjustment.

          (c) In case of any capital reorganization, any reclassification of the
     Common Stock (other than a change in par value or recapitalization
     described in Paragraph 7(a) of this Option Agreement), or the consolidation
     of the Company with, or a sale of substantially all of the assets of the
     Company to (which sale is followed by a liquidation or dissolution of the
     Company), or merger of the Company with another person (a "Reorganization
     Event"), the Board (or a committee thereof) shall be obligated to determine
     whether the Reorganization Event shall constitute a "Liquidity Event," and
     to deliver to Optionee at least 15 days prior to such Reorganization Event
     a notice which shall (i) indicate whether the Reorganization Event is a
     Liquidity Event; (ii) indicate whether the Liquidity Event shall result in
     the acceleration of the vesting provisions of this Option; and (iii) advise
     Optionee of his or her fights pursuant to this Option Agreement. If the
     Reorganization Event is determined to be a Liquidity Event, in its sole and
     absolute discretion, the surviving corporation may, but shall not be
     obligated to, (i) tender to Optionee Stock Options with respect to the
     surviving corporation which shall contain terms and provisions that
     substantially preserve the rights and benefits of this Option, and (ii) in
     the event that no Stock Options have been tendered by the surviving
     corporation pursuant to the terms of item (i) immediately above, Optionee
     shall have the right exercisable during a ten-day period ending on the
     fifth day prior to the Reorganization Event (or ending on the fifth day
     prior to the date of record for shareholders entitled to share in the
     securities or property distributed in the Reorganization Event, if a record
     date is set) to exercise his or her Stock Options in whole or in part, and
     if so determined by the Board (or a committee thereof), without regard to
     any installment provisions under his or her Stock Option Agreement, on the
     condition, however, that the Reorganization Event is actually effected; and
     if the Reorganization Event is actually effected, such exercise shall be
     deemed effective (and, if applicable, the Optionee shall be deemed a
     shareholder with respect to the Stock Options exercised) immediately
     preceding the effective time of the Reorganization Event (or on the date of
     record for shareholders entitled to share in the securities or property
     distributed in the Reorganization Event, if a record date is set). If the
     Reorganization Event is not determined to be a Liquidity Event, Optionee
     shall thereafter be entitled upon exercise of the Option to purchase the
     kind and number of shares of stock or other securities or property of the
     surviving corporation receivable upon such event by a holder of the number
     of shares of the Common Stock which the Option entitles Optionee to
     purchase from the Company immediately prior to such event, and in any such
     case, appropriate adjustment shall be made in the application of the
     provisions set forth in this Option Agreement with respect to Optionee's
     rights and interests


                                  EX-10-8 - 9
<PAGE>


     thereafter, to the end that the provisions set forth in this Option
     Agreement (including the specified changes and other adjustments to the
     Exercise Price) shall thereafter be applicable in relation to any shares or
     other property thereafter purchasable upon exercise of the Option.

          (d) In the event of the proposed dissolution or liquidation of the
     Company, or in the event of any corporate separation or division,
     including, but not limited to, a split-up, split-off or spin-off (each, a
     "Liquidating Event"), the holder of any Stock Option then exercisable shall
     have the right to exercise such Stock Option (at the price provided in the
     Stock Option Agreement) subsequent to the Liquidating Event, and for the
     balance of its term, solely for the kind and amount of shares of Stock and
     other securities, property, cash or any combination thereof receivable upon
     such Liquidating Event by a holder of the number of shares of Stock for or
     with respect to which such Stock Option might have been exercised
     immediately prior to such Liquidating Event; or, in the alternative, that
     each Stock Option granted shall terminate as of a date to be fixed by the
     Board (or a committee thereof); provided, however, that not less than 30
     days written notice of the date so fixed shall be given to each Option
     Holder and if such notice is given, each Option Holder shall have the
     right, during the period of 30 days preceding such termination, to exercise
     the Stock Option as to all or any part of the shares of Stock covered
     thereby, without regard to installment or vesting provisions in Section 3
     of this Option Agreement, on the condition, however, that the Liquidating
     Event actually occurs; and if the Liquidating Event actually occurs, such
     exercise shall be deemed effective (and, if applicable, the Option Holder
     shall be deemed a shareholder with respect to the Stock Options exercised)
     immediately preceding the occurrence of the Liquidating Event, or the date
     of record for shareholders entitled to share in such Liquidating Event, if
     a record date is set.

          (e) To the extent that the foregoing adjustments relate to stock or
     securities of the Company, such adjustments shall be made by the Board (or
     a committee thereof), and their determination shall be final, binding and
     conclusive.

          (f) The provisions of this Paragraph 7 are intended to be exclusive,
     and Optionee shall have no other fights upon the occurrence of any of the
     events described in this Paragraph 7.

          (g) The grant of the Option shall not affect in any way the fight or
     power of the Company to make adjustments, reclassifications,
     reorganizations or changes in its capital or business structure, or to
     merge, consolidate, dissolve or liquidate, or to sell or transfer all or
     any part of its business or assets.


                                  EX-10-8 - 10
<PAGE>


     8. Waiver of Rights to Purchase Stock.

     By signing this Option Agreement, Optionee acknowledges and agrees that
neither the Company nor any other person or entity is under any obligation to
sell or transfer to Optionee any option or equity security of the Company, other
than the shares of Common Stock subject to the Option and any other fight or
option to purchase Common Stock which was previously granted to Optionee by the
Board (or a committee thereof). By signing this Option Agreement, Optionee
specifically waives all fights which he may have had prior to the date of this
Option Agreement to receive any option or equity security of the Company.

     9. Investment Intent.

     Optionee represents and agrees that if he exercises the Option in whole or
in part and if at the time of such exercise the Purchased Shares have not been
registered under the Act, he will acquire the Shares upon such exercise for the
purpose of investment and not with a view to the distribution of such Shares,
and that upon each exercise of the Option he will furnish to the Company a
written statement to such effect, if so requested by the Company.

     10. Legend on Stock Certificates.

     Optionee agrees that all certificates representing the Purchased Shares
will be subject to such stock transfer orders and other restrictions (if any) as
the Company may deem advisable under the rules, regulations and other
requirements of the Securities and Exchange Commission, any stock exchange upon
which the `Common Stock is then listed and any applicable federal or state
securities laws, and the Company may cause a legend or legends to be put on such
certificates to make appropriate reference to such restrictions.

     11. No Rights as Shareholder.

     Optionee shall have no rights as a shareholder with respect to the Shares
until the date of the issuance to Optionee of a stock certificate or stock
certificates evidencing such Shares. Except as may be provided in Paragraph 7 of
this Option Agreement, no adjustment shall be made for dividends (ordinary or
extraordinary, whether in cash, securities or other property) or distributions
or other rights for which the record date is prior to the date such stock
certificate is issued.

     12. Modification.

     The Board (or a committee thereof) may modify, extend or renew the Option
or accept the surrender of, and authorize the grant of a new option in
substitution for, the


                                  EX-10-8 - 11
<PAGE>


Option (to the extent not previously exercised).

     13. Withholding.

          (a) The Company shall be entitled to require as a condition of
     delivery of any Purchased Shares upon exercise of any Option that the
     Optionee agree to remit, at the time of such delivery or at such later date
     as the Company may determine, an amount sufficient to satisfy all federal,
     state and local withholding tax requirements relating thereto, and Optionee
     agrees to take such other action required by the Company to satisfy such
     withholding requirements.

          (b) With the consent of the Board (or a committee thereof), and in
     accordance with any rules and procedures from time to time adopted by the
     Board (or a committee thereof), Optionee may elect to satisfy his or her
     obligations under Paragraph 13(a) above by (i) directing the Company to
     withhold a portion of the Shares otherwise deliverable (or to tender back
     to the Company a portion of the Shares issued where the Optionee (a
     "Section 16(b) Recipient") is required to report the ownership of the
     Shares pursuant to Section 16(a) of the Securities Exchange Act of 1934, as
     amended, and has not made an election under Section 83(b) of the Code (a
     "Withholding Right")); or (ii) tendering other shares of the Common Stock
     of the Company which are already owned by Optionee which in all cases have
     a fair market value (as determined in accordance with the provisions of
     Paragraph 4(b) hereof) on the date as of which the amount of tax to be
     withheld is determined (the "Tax Date") equal to the amount of taxes to be
     paid by such method.

          (c) To exercise a Withholding Right, the Optionee must follow the
     election procedures set forth below, together with such additional
     procedures and conditions set forth in this Option Agreement or otherwise
     adopted by the Board (or a committee thereof):

               (i) the Optionee must deliver to the Company his or her written
          notice of election (the "Election") and specify whether all or a
          stated percentage of the applicable taxes will be paid in accordance
          with Paragraph 13(b) above and whether the amount so paid shall be
          made in accordance with the "flat" withholding rates for supplemental
          wages or as determined in accordance with Optionee's form W-4 (or
          comparable state or local form);

               (ii) unless disapproved by the Board (or a committee thereof) or
          as provided in Subsection (iii) below, the Election once made will be
          irrevocable; and


                                  EX-10-8 - 12
<PAGE>


               (iii) no Election is valid unless the Board (or a committee
          thereof) consents to the Election; the Board (or a committee thereof)
          has the right and power, in its sole discretion, with or without cause
          or reason therefor, to consent to the Election, to refuse to consent
          to the Election, or to disapprove the Election; and if the Board (or a
          committee thereof) has not consented to the Election on or prior to
          the Tax Date, the Election will be deemed approved.

               (iv) If the Optionee on the date of delivery of the Election to
          the Company is a Section 16(b) Recipient, the following additional
          provisions will apply:

                    (a) the Election cannot be made during the six calendar
               month period commencing with the date of ant of the Withholding
               Right (even if the Option to which such Withholding Right relates
               has been granted prior to such date); and

                    (b) the Election must be made on a date which is six
               calendar months or more prior to the Tax Date.

     14. Character of Option.

          The Option is not intended to qualify as an "incentive stock option"as
     that term is defined in Section 422 of the Code.

     15. General Provisions.

          (a) Further Assurances. Optionee shall promptly take all actions and
     execute all documents requested by the Company which the Company deems to
     be reasonably necessary to effectuate the terms and intent of this Option
     Agreement.

          (b) Notices. All notices, requests, demands and other communications
     under this Option Agreement shall be in writing and shall be given to the
     parties hereto as follows:

          If to the Company, to:

               BioSource International, Inc.
               820 Flynn Road
               Camarillo, California 93012
               Attention: Secretary

          If to Optionee, to the address set forth in the records of the
     Company,


                                  EX-10-8 - 13
<PAGE>


or at such other address or addresses as may have been furnished by such either
party in writing to the other party hereto. Any such notice, request, demand or
other communication shall be effective (i) if given by mail, 72 hours after such
communication is deposited in the mail by first class certified mail, return
receipt requested, postage prepaid, addressed as aforesaid, or (ii) if given by
any other means, when delivered at the address specified in this subparagraph
(b).

          (c) Transfer of Rights under this Option Agreement. The Company may at
     any time transfer and assign its rights and delegate its obligations under
     this Option Agreement to any other person, corporation, firm or entity,
     including its officers, directors and stockholders, with or without
     consideration.

          (d) Option Non-Transferable. Optionee may not sell, transfer, assign
     or otherwise dispose of the Option except by will or the laws of descent
     and distribution and Stock Options may be exercised during the lifetime of
     the Option Holder only by the Option Holder or by his or her guardian or
     legal representative.

          (e) Successors and Assigns. Except to the extent specifically limited
     by the terms and provisions of this Option Agreement, this Option Agreement
     shall be binding upon and inure to the benefit of the parties hereto and
     their respective successors, assigns, heirs and personal representatives.

          (f) Governing Law. THIS OPTION AGREEMENT SHALL BE GOVERNED BY AND
     CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE LAWS OF THE STATE OF
     CALIFORNIA APPLICABLE TO CONTRACTS MADE IN, AND TO BE PERFORMED WITHIN,
     THAT STATE.

          (g) Miscellaneous. Titles and captions contained in this Option
     Agreement are inserted for convenience of reference only and do not
     constitute a part of this Option Agreement for any other purpose. Except as
     specifically provided herein, neither this Option Agreement nor any right
     pursuant hereto or interest herein shall be assignable by any of the
     parties hereto without the prior written consent of the other party hereto.

                   The Signature Page to this Option Agreement
                  consists of the last page of the Certificate.


                                  EX-10-8 - 14
<PAGE>


                                   Exhibit "A"

                               NOTICE OF EXERCISE

                 (To be signed only upon exercise of the Option)

TO: BioSource International, Inc.

     The undersigned, the holder of the enclosed Stock Option Agreement (Non
Statutory Stock Option), hereby irrevocably elects to exercise the purchase
fights represented by the Option and to purchase thereunder _______________*
shares of Common Stock of BioSource International, Inc. (the "Company"), and
herewith encloses payment of $_______________ and/or ______________shares of the
Company's Common Stock in full payment of the purchase price of such shares
being purchased.

Dated: ________________________

                                             --------------------------------
                                              (Signature must conform in all
                                              respects to name of holder as
                                            specified on the face of the Option)



                                             -----------------------------------
                                             (Please Print Name)



                                             -----------------------------------
                                             (Address)


                                  EX-10-8 - 15
<PAGE>


     * Insert here the number of shares called for on the face of the Option
(or, in the case of a partial exercise, the number of shares being exercised),
in either case without making any adjustment for additional Common Stock of the
Company, other securities or property which, pursuant to the adjustment
provisions of the Option, may be deliverable upon exercise.


                                  EX-10-8 - 16