EXHIBIT 10.23

                         EXECUTIVE EMPLOYMENT AGREEMENT

         This Executive  Employment  Agreement  (this  "AGREEMENT")  is made and
entered  into as of this 8th day of  October,  2003,  by and  between  BioSource
International,  Inc., a Delaware  corporation  (the  "COMPANY") and Terry Bieker
("EXECUTIVE").

1.       ENGAGEMENT AND DUTIES.

         1.1      Commencing upon November 1st, 2003 (the "EFFECTIVE DATE"), and
upon the terms and subject to the  conditions set forth in this  Agreement,  the
Company hereby engages and employs Executive as an officer of the Company,  with
the title and  designation  of  President  and Chief  Executive  Officer  of the
Company.  Executive  hereby accepts such  engagement and  employment.  Executive
shall also be appointed to fill the current vacancy on the Board, and so long as
Executive serves in the capacity of President and Chief Executive Officer of the
Company,  the Board  shall  nominate  Executive  to serve as a  Director  of the
Company,  and  shall  use its  commercially  reasonable  efforts  to  cause  the
stockholders of the Company to so elect Executive.

         1.2      Executive's  duties  and   responsibilities   shall  be  those
normally and customarily  vested in the offices of President and Chief Executive
Officer of a corporation,  subject to the supervision,  direction and control of
the Board of Directors  (the "BOARD") of the Company.  In addition,  Executive's
duties  shall  include  those  duties  and  services  for  the  Company  and its
affiliates  as the Board shall from time to time  reasonably  direct.  Executive
shall report directly to the Board.

         1.3      Executive   agrees  to  devote  his  primary   business  time,
energies,  skills, efforts and attention to his duties hereunder,  and will not,
without the prior  written  consent of the  Company,  which  consent will not be
unreasonably  withheld,  render  any  material  services  to any other  business
concern.  Executive  will use his best  efforts  and  abilities  faithfully  and
diligently to promote the Company's business interests.

         1.4      Except for  routine  travel  incident  to the  business of the
Company, Executive shall perform his duties and obligations under this Agreement
principally from an office provided by the Company in Camarillo,  California, or
such other location in Los Angeles or Ventura County,  California,  as the Board
may from time to time determine.

2.       TERM OF EMPLOYMENT.  Executive's  employment pursuant to this Agreement
shall  commence on the  Effective  Date and shall  terminate  on the earliest to
occur of the following:

         (a)      the close of business on December 31, 2007;

         (b)      the death of Executive;

         (c)      delivery to Executive of written  notice of termination by the
                  Company if Executive  shall  suffer a "permanent  disability,"
                  which for purposes of this Agreement  shall mean a physical or
                  mental  disability  which,  in the reasonable  judgment of the
                  Board,  is likely to render  Executive  unable to perform  his
                  duties and obligations under this Agreement for 90 days in any
                  12-month period;


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         (d)      delivery to Executive of written  notice of termination by the
                  Company  "for  cause," by reason  of: (i) any act or  omission
                  knowingly  undertaken or omitted by Executive  with the intent
                  of causing damage to the Company,  its  properties,  assets or
                  business  or  its   stockholders,   officers,   directors   or
                  employees;  (ii) any act of  Executive  involving  a  material
                  personal profit to Executive,  including,  without limitation,
                  any  fraud,   misappropriation   or  embezzlement,   involving
                  properties,  assets  or  funds  of the  Company  or any of its
                  subsidiaries;  (iii) Executive's consistent failure to perform
                  his normal  duties or any  obligation  under any  provision of
                  this Agreement, in either case, as directed by the Board; (iv)
                  conviction  of, or pleading nolo  contendere to, (A) any crime
                  or offense  involving monies or other property of the Company;
                  (B) any felony offense;  or (C) any crime of moral  turpitude;
                  or (v) the chronic or habitual use or  consumption of drugs or
                  alcoholic beverages; or

         (e)      delivery to Executive of written  notice of termination by the
                  Company "without cause."

3.       COMPENSATION; EXECUTIVE BENEFIT PLANS.

         3.1      The Company  shall pay to Executive a base salary at an annual
rate  of  $275,000  during  each  fiscal  year  of this  Agreement,  subject  to
adjustment on an annual basis by the Board.  The base salary shall be payable in
installments  throughout  the year in the same  manner and at the same times the
Company pays base salaries to other  executive  officers of the Company.  In the
event that Executive's employment is terminated pursuant to SECTION 2(E), above,
the Company shall  continue to pay  Executive's  then-current  base salary for a
period  of 12 months  following  the  effective  date of such  termination,  and
Executive shall retain only those options  described in SECTION 3.4, below, that
have vested prior to the effective date of such termination. Notwithstanding the
foregoing,  the Company  shall not be  obligated  to pay  Executive  any amounts
hereunder  following  the  termination  of  Executive's  employment  pursuant to
SECTION  2(E),  above,  from  and  after  any time  that  Executive  accepts  an
employment or  consulting  position with any person or entity that is determined
by the Board, in the exercise of its reasonable  discretion,  to be a competitor
of the Company.

         3.2      In  addition  to the  base  salary  to be  paid  to  Executive
hereunder,  the Company shall pay a bonus to Executive a signing bonus of Ninety
Thousand  Dollars  ($90,000),  payable on the Effective  Date, and a performance
bonus (the "BONUS") determined in accordance with a management incentive plan to
be  agreed  upon  between  Executive  and the  Board  on an  annual  basis.  The
management incentive plan will provide for the payment of a Bonus equal to fifty
percent  (50%) of  Executive's  then-current  base  salary  upon  achieving  the
"target" objectives set forth in the management  incentive plan, and payments of
such lesser or greater amounts upon achieving  results less than or greater than
the "target" objectives as shall be contained in the management incentive plan.

         3.3      Executive  shall  be  entitled  each  year to  vacation  for a
minimum of four calendar weeks,  plus such  additional  period or periods as the
Board may approve in the  exercise of its  reasonable  discretion,  during which
time his compensation shall be paid in full.

         3.4      Executive  shall be  granted  an  option to  purchase  285,000
shares of Common Stock at a per share  exercise  price equal to the "fair market
value" of such shares on the Effective  Date (as defined in the  Company's  2000
Stock Incentive Plan (the "STOCK  PLAN")).  The Options shall be issued pursuant
to the terms of the Stock  Plan,  and shall vest as to 25% of the Options on


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the first  anniversary  of the date of grant,  and as to 1/48th of the Option on
the last day of each calendar month  thereafter  until fully vested.  The option
agreement  will  provide for the  acceleration  of all vesting  upon a change of
control, as defined in the option agreement.

         3.5      Executive shall be entitled to reimbursement  from the Company
for the  reasonable  costs and expenses  which he incurs in connection  with the
performance  of his duties and  obligations  under  this  Agreement  in a manner
consistent with the Company's practices and policies as adopted or approved from
time to time by the Board for executive officers. In addition,  the Company will
pay to Executive,  for the costs and expenses to be incurred in connection  with
his  relocation  to  California,  an amount equal to $235,000  (the  "RELOCATION
EXPENSE").  The  Company  will pay the  Relocation  Expense in cash at such time
following the Effective  Date as may be requested by Executive,  but in no event
later than sixty (60) days following such date.

         3.6      The  Company  may  deduct  from any  compensation  payable  to
Executive the minimum  amounts  sufficient to cover  applicable  federal,  state
and/or local income tax  withholding,  old-age and  survivors'  and other social
security payments, state disability and other insurance premiums and payments.

4.       OTHER BENEFITS. During the term of his employment hereunder,  Executive
shall be eligible to participate in all operative  employee  benefit and welfare
plans of the  Company  then in effect  from time to time and in respect of which
all  executive  officers of the Company  generally  are entitled to  participate
("COMPANY  EXECUTIVE BENEFIT PLANS"),  including,  to the extent then in effect,
group life, medical, disability and other insurance plans, all on the same basis
applicable to employees of the Company  whose level of management  and authority
is comparable to that of Executive.

5.       CONFIDENTIALITY OF PROPRIETARY INFORMATION AND MATERIAL.

         5.1      INDUSTRIAL PROPERTY RIGHTS. For the purpose of this Agreement,
"INDUSTRIAL   PROPERTY  RIGHTS"  shall  mean  all  of  the  Company's   patents,
trademarks,  trade names,  inventions,  copyrights,  know-how or trade  secrets,
formulas and science, now in existence or hereafter developed or acquired by the
Company or for its use,  relating to any and all products and services which are
developed, formulated and/or manufactured by the Company.

         5.2      TRADE  SECRETS.  For the  purpose  of this  Agreement,  "TRADE
SECRETS" shall mean any formula,  pattern, device, or compilation of information
that is used in the Company's  business and gives the Company an  opportunity to
obtain an advantage over its  competitors  who do not know and/or do not use it.
This term includes, but is not limited to, information relating to the marketing
of  the  Company's  products  and  services,   including  price  lists,  pricing
information,  customer lists, customer names, the particular needs of customers,
information relating to their desirability as customers,  financial information,
intangible  property  and  other  such  information  which is not in the  public
domain.

         5.3      TECHNICAL DATA. For the purpose of this Agreement,  "TECHNICAL
DATA" shall mean all information of the Company in written,  graphic or tangible
form relating to any and all products  which are  developed,  formulated  and/or
manufactured by the Company, as such information exists as of the Effective Date
or is developed by the Company during the term hereof.

         5.4      PROPRIETARY  INFORMATION.  For the purpose of this  Agreement,
"PROPRIETARY  INFORMATION" shall mean all of the Company's  Industrial  Property
Rights, Trade Secrets and


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Technical Data. Proprietary  Information shall not include any information which
(i) was lawfully in the possession of Executive prior to Executive's  employment
with the Company,  (ii) may be obtained by a reasonably diligent  businessperson
from readily  available  and public  sources of  information,  (iii) is lawfully
disclosed to Executive  after  termination of Executive's  employment by a third
party which does not have an obligation to the Company to keep such  information
confidential,  or (iv) is independently developed by Executive after termination
of Executive's  employment  without  utilizing any of the Company's  Proprietary
Information.

         5.5      AGREEMENT NOT TO COPY OR USE.  Executive  agrees,  at any time
during the term of his employment and for a period of ten years thereafter,  not
to copy,  use or disclose  (except as required by law after first  notifying the
Company  and giving it an  opportunity  to object) any  Proprietary  Information
without the Company's  prior written  permission.  The Company may withhold such
permission  as a matter  within  its  sole  discretion  during  the term of this
Agreement and thereafter.

6.       RETURN OF CORPORATE PROPERTY AND TRADE SECRETS. Upon any termination of
this Agreement,  Executive shall turn over to the Company all property, writings
or documents then in his  possession or custody  belonging to or relating to the
affairs of the Company or comprising or relating to any Proprietary Information.

7.       DISCOVERIES AND INVENTIONS.

         7.1      DISCLOSURE. Executive will promptly disclose in writing to the
Company complete  information  concerning each and every  invention,  discovery,
improvement,  device, design, apparatus,  practice,  process, method, product or
work of  authorship,  whether  patentable or not,  made,  developed,  perfected,
devised,  conceived or first  reduced to practice by  Executive,  whether or not
during regular working hours (hereinafter referred to as "Developments"), either
solely or in collaboration  with others, (a) prior to the term of this Agreement
while  working for the  Company,  (b) during the term of this  Agreement  or (c)
within six months after the term of this Agreement,  if relating either directly
or indirectly to the business, products,  practices,  techniques or confidential
information of the Company.

         7.2      ASSIGNMENT.  Executive,  to the  extent  that he has the legal
right  to do so,  hereby  acknowledges  that  any and all  Developments  are the
property of the  Company and hereby  assigns and agrees to assign to the Company
any and all of  Executive's  right,  title and interest in and to any and all of
such Developments;  PROVIDED, HOWEVER, that, in accordance with California Labor
Code Sections 2870 and 2872,  the provisions of this SECTION 7.2 shall not apply
to any Development that the Executive developed entirely on his own time without
using the Company's equipment,  supplies, facilities or trade secret information
except for those Developments that either:

                  (a)      relate  at the time of  conception  or  reduction  to
                           practice  of  the   Development   to  the   Company's
                           business,  or  actual  or  demonstrably   anticipated
                           research or development of the Company; or

                  (b)      result from any work  performed by Executive  for the
                           Company.

         7.3      ASSISTANCE  OF  EXECUTIVE.  Upon  request and without  further
compensation  therefor,  but at no expense to Executive,  and whether during the
term of this  Agreement or thereafter,  Executive will do all reasonable  lawful
acts,  including,  but not limited to, the  execution of papers and lawful oaths
and the giving of testimony, that, in the reasonable opinion of the


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Company, its successors and assigns, may be necessary or desirable in obtaining,
sustaining, reissuing, extending and enforcing United States and foreign Letters
Patent,  including,  but  not  limited  to,  design  patents,  on  any  and  all
Developments and for perfecting,  affirming and recording the Company's complete
ownership and title thereto,  subject to the proviso in SECTION 7.2 hereof,  and
Executive will otherwise  reasonably  cooperate in all  proceedings  and matters
relating thereto.

         7.4      RECORDS.  Executive will keep complete and accurate  accounts,
notes,  data and records of all Developments in the manner and form requested by
the Company. Such accounts, notes, data and records shall be the property of the
Company,  subject to the proviso in SECTION 7.2 hereof, and, upon request by the
Company,  Executive will promptly surrender the same to it or, if not previously
surrendered  upon its request or otherwise,  Executive  will surrender the same,
and all copies thereof, to the Company upon the conclusion of his employment.

         7.5      OBLIGATIONS,    RESTRICTIONS   AND   LIMITATIONS.    Executive
understands  that the Company may enter into  agreements  or  arrangements  with
agencies of the United States  Government and that the Company may be subject to
laws and regulations which impose  obligations,  restrictions and limitations on
it with respect to  inventions  and patents which may be acquired by it or which
may be  conceived  or  developed  by  employees,  consultants  or  other  agents
rendering  services to it.  Executive  agrees that he shall be bound by all such
obligations,  restrictions  and  limitations  applicable  to any such  invention
conceived or developed by him during the term of this  Agreement  and shall take
any and all further action which may be required to discharge  such  obligations
and to comply with such restrictions and limitations.

8.       NON-SOLICITATION COVENANT.

         8.1      NONSOLICITATION AND  NONINTERFERENCE.  During the term of this
Agreement  and for a period of two  years  thereafter,  Executive  shall not (a)
induce or attempt to induce any  employee  of the Company to leave the employ of
the Company or in any way interfere adversely with the relationship  between any
such  employee and the Company,  (b) induce or attempt to induce any employee of
the  Company  to work  for,  render  services  or  provide  advice  to or supply
confidential  business  information or trade secrets of the Company to any third
person,  firm or  corporation  or (c) induce or attempt to induce any  customer,
supplier,  licensee, licensor or other business relation of the Company to cease
doing  business with the Company or in any way interfere  with the  relationship
between  any such  customer,  supplier,  licensee,  licensor  or other  business
relation and the Company.

         8.2      INDIRECT SOLICITATION.  Executive agrees that, during the term
of this  Agreement  and the period  covered by SECTION 8.1 hereof,  he will not,
directly or  indirectly,  assist or encourage  any other person in carrying out,
directly or indirectly,  any activity that would be prohibited by the provisions
of SECTION 8.1 if such activity were carried out by Executive,  either  directly
or indirectly;  and, in particular,  Executive agrees that he will not, directly
or  indirectly,  induce any  employee of the  Company to carry out,  directly or
indirectly, any such activity.

9.       INJUNCTIVE RELIEF. Executive hereby recognizes, acknowledges and agrees
that  in the  event  of  any  breach  by  Executive  of  any  of his  covenants,
agreements,  duties or  obligations  contained in SECTIONS 5, 6, 7 AND 8 of this
Agreement,  the Company  would suffer  great and  irreparable  harm,  injury and
damage,  the Company would encounter  extreme  difficulty in attempting to prove
the actual amount of damages suffered by the Company as a result of such breach,
and the Company would not be reasonably or adequately  compensated in damages in
any action at law.


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Executive  therefore  covenants and agrees that, in addition to any other remedy
the Company may have at law, in equity, by statute or otherwise, in the event of
any  breach  by  Executive  of any  of  his  covenants,  agreements,  duties  or
obligations  contained in SECTIONS 5, 6, 7 AND 8 of this Agreement,  the Company
shall be entitled  to seek and  receive  temporary,  preliminary  and  permanent
injunctive and other equitable  relief from any court of competent  jurisdiction
to  enforce  any  of  the  rights  of the  Company,  or  any  of the  covenants,
agreements,  duties or obligations of Executive  hereunder,  and/or otherwise to
prevent the violation of any of the terms or provisions  hereof, all without the
necessity  of  proving  the amount of any  actual  damage to the  Company or any
affiliate thereof resulting therefrom; provided, however, that nothing contained
in this  SECTION 9 shall be deemed or construed  in any manner  whatsoever  as a
waiver by the Company of any of the rights  which the  Company may have  against
Executive  at law,  in  equity,  by  statute  or  otherwise  arising  out of, in
connection  with  or  resulting  from  the  breach  by  Executive  of any of his
covenants, agreements, duties or obligations hereunder.

10.      MISCELLANEOUS.

         10.1     ARBITRATION.  The parties  agree that they will use their best
efforts to  amicably  resolve  any  dispute  arising  out of or relating to this
Agreement. Any controversy, claim or dispute that cannot be so resolved shall be
settled  by final  binding  arbitration  in  accordance  with  the  rules of the
American  Arbitration  Association  and judgment upon the award  rendered by the
arbitrator  or  arbitrators  may be  entered  in any court  having  jurisdiction
thereof.  Any such  arbitration  shall be  conducted  in Los  Angeles  County or
Ventura County,  California,  or such other place as may be mutually agreed upon
by  the  parties.  Within  fifteen  (15)  days  after  the  commencement  of the
arbitration,  each party shall select one person to act arbitrator,  and the two
arbitrators so selected shall select a third arbitrator  within ten (10) days of
their appointment. Each party shall bear its own costs and expenses and an equal
share of the arbitrator's expenses and administrative fees of arbitration.

         10.2     NOTICES.  All  notices,   requests  and  other  communications
(collectively,  "NOTICES") given pursuant to this Agreement shall be in writing,
and shall be  delivered  by personal  service or by United  States  first class,
registered  or  certified  mail (return  receipt  requested),  postage  prepaid,
addressed to the party at the address set forth below:

                  If to Company:

                           BioSource International, Inc.
                           542 Flynn Road
                           Camarillo, CA 93012
                           Attn: Board of Directors

                  If to Executive,  at the address  maintained  for Executive in
the Company's payroll records.

                  Any Notice  shall be deemed  duly given when  received  by the
addressee thereof, provided that any Notice sent by registered or certified mail
shall be deemed to have been duly  given  three days from date of deposit in the
United States mails, unless sooner received.  Either party may from time to time
change its address for further  Notices  hereunder by giving notice to the other
party in the manner prescribed in this section.


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         10.3     ENTIRE AGREEMENT.  This Agreement contains the sole and entire
agreement and  understanding  of the parties with respect to the entire  subject
matter  of  this  Agreement,  and any and  all  prior  agreements,  discussions,
negotiations, commitments and understandings, whether oral or otherwise, related
to  the  subject  matter  of  this  Agreement  are  hereby  merged  herein.   No
representations,  oral or  otherwise,  express  or  implied,  other  than  those
contained  in  this  Agreement  have  been  relied  upon  by any  party  to this
Agreement.

         10.4     ATTORNEYS'  FEES. If any action,  suit or other  proceeding is
instituted to remedy, prevent or obtain relief from a default in the performance
by any party of its obligations under this Agreement, the prevailing party shall
recover all of such party's  costs and  reasonable  attorneys'  fees incurred in
each and every such  action,  suit or other  proceeding,  including  any and all
appeals or petitions therefrom.

         10.5     GOVERNING  LAW.  THIS  AGREEMENT  SHALL  BE  GOVERNED  BY  AND
CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF CALIFORNIA, WITHOUT REGARD
TO CONFLICTS OF LAW PRINCIPLES THEREOF.

         10.6     CAPTIONS.  The  various  captions  of this  Agreement  are for
reference only and shall not be considered or referred to in resolving questions
of interpretation of this Agreement.

         10.7     COUNTERPARTS.  This Agreement may be executed in any number of
counterparts,  each of which shall be deemed to be an original, but all of which
together shall constitute one and the same instrument.

         10.8     BUSINESS DAY. If the last day  permissible for delivery of any
Notice under any  provision of this  Agreement,  or for the  performance  of any
obligation  under this Agreement,  shall be other than a business day, such last
day for such  Notice or  performance  shall be  extended  to the next  following
business day (provided,  however, under no circumstances shall this provision be
construed to extend the date of termination of this Agreement).

         In witness whereof,  the parties have executed this Agreement as of the
date first set forth above.

Company:                                       Executive:

BIOSOURCE INTERNATIONAL, INC.



By: /s/ Jean Pierre Conte                      /s/ Terry Bieker
    -----------------------------------        --------------------------------
    Jean Pierre Conte,                         Terry Bieker
    Chairman of the Board


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