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                                                                     EXHIBIT 4.2

                                PLEDGE AGREEMENT

          THIS PLEDGE AGREEMENT (as the same many be amended, restated,
supplemented or otherwise modified from time to time, the "Pledge Agreement"),
dated as of September 9, 2003, is executed by and between Bio-Rad Laboratories,
Inc., a Delaware corporation (together with its successors and assigns, the
"Pledgor"), and Bank One, NA (Main Office Chicago), as contractual
representative (the "Administrative Agent") for itself and for the "Holders of
Secured Obligations" under (and as defined in) the Credit Agreement (as defined
below). Capitalized terms used herein and not otherwise defined herein shall
have the respective meanings ascribed to such terms in the Credit Agreement.

                                    RECITALS:

          WHEREAS, the Pledgor, the Administrative Agent and certain financial
institutions (the "Lenders") have entered into a certain Credit Agreement of
even date herewith (as the same may be amended, restated, supplemented or
otherwise modified from time to time, the "Credit Agreement"), pursuant to which
the Lenders have agreed, subject to certain conditions precedent, to make loans
and other financial accommodations to the Pledgor from time to time;

          WHEREAS, the Credit Agreement provides for the making of advances,
loans and other financial accommodations (including, without limitation, letters
of credit) by the Lenders in favor of the Pledgor (all such loans, advances and
other financial accommodations being hereinafter referred to collectively as the
"Loans");

          WHEREAS, Schedule I hereto sets forth certain of the Pledgor's
Subsidiaries (the "Initial Pledged Subsidiaries");

          WHEREAS, to the extent permitted under the Credit Agreement, the
Pledgor may from time to time execute and deliver to the Administrative Agent a
supplement to this Pledge Agreement substantially in the form of Exhibit A
hereto (each such supplement, a "Pledge Supplement") setting forth additional
Subsidiaries of the Pledgor (the "Additional Pledged Subsidiaries") (the Initial
Pledged Subsidiaries and the Additional Pledged Subsidiaries, collectively
referred to herein as the "Pledged Subsidiaries"); and

          WHEREAS, the Administrative Agent and the Lenders have required, as a
condition to their entering into the Credit Agreement, that the Pledgor execute
and deliver this Pledge Agreement;

          NOW, THEREFORE, for and in consideration of the foregoing and of any
financial accommodations or extensions of credit (including, without limitation,
any loan or advance by renewal, refinancing or extension of the agreements
described hereinabove or otherwise) heretofore, now or hereafter made to or for
the benefit of the Pledgor pursuant to the Credit Agreement or any other
agreement, instrument or document executed pursuant to or in connection
therewith, and for other good and valuable consideration, the receipt and
sufficiency

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of which are hereby acknowledged, the Pledgor and the Administrative Agent
hereby agree as follows:

          SECTION 1. Pledge. The Pledgor hereby pledges to the Administrative
Agent, for the benefit of the Administrative Agent and the Holders of Secured
Obligations, and grants to the Administrative Agent, for the benefit of the
Administrative Agent and the Holders of Secured Obligations, a security interest
in, the collateral described in subsections (a) through (e) below (collectively,
the "Pledged Collateral"):

          (a) (i) All of the capital stock of the Pledged Subsidiaries listed on
     Schedule I which are corporations, now or at any time or times hereafter
     owned directly by the Pledgor (such shares being identified on Schedule I
     attached hereto or on any Schedule I attached to any applicable Pledge
     Supplement), and the certificates representing the shares of such capital
     stock, all options and warrants for the purchase of shares of the stock of
     such Pledged Subsidiaries now or hereafter held in the name of the Pledgor
     (all of said capital stock, options and warrants and all capital stock held
     in the name of the Pledgor as a result of the exercise of such options or
     warrants being hereinafter collectively referred to as the "Pledged
     Stock"), herewith, or from time to time, delivered to the Administrative
     Agent accompanied by stock powers in the form of Exhibit B attached hereto
     and made a part hereof (the "Powers") duly executed in blank, and all
     dividends, cash, instruments, investment property and other property from
     time to time received, receivable or otherwise distributed in respect of,
     or in exchange for, any or all of the Pledged Stock;

               (ii) All additional shares of capital stock of the Pledged
     Subsidiaries described in Section 1(a)(i) above from time to time acquired
     by the Pledgor in any manner, and the certificates, which shall be
     delivered to the Administrative Agent accompanied by Powers duly executed
     in blank, representing such additional shares (any such additional shares
     shall constitute part of the Pledged Stock, and the Administrative Agent is
     irrevocably authorized to unilaterally amend Schedule I hereto or any
     Schedule I to any applicable Pledge Supplement to reflect such additional
     shares), and all options, warrants, dividends, cash, instruments,
     investment property and other rights and options from time to time
     received, receivable or otherwise distributed in respect of or in exchange
     for any or all of such shares;

          (b) (i) All of the membership interests of Pledgor in the Pledged
     Subsidiaries listed on Schedule I which are limited liability companies now
     or at any time or times hereafter owned directly by the Pledgor, and any
     certificates representing such membership interests in the Pledged
     Subsidiaries (such membership interests being identified on Schedule I
     attached hereto or on any Schedule I attached to any applicable Pledge
     Supplement), all of the right, title and interest of the Pledgor in, to and
     under its respective percentage interest, shares or units as a member and
     all investment property in respect of such membership interests, including,
     without limitation, Pledgor's interest in (or allocation of) the profits,
     losses, income, gains, deductions, credits or similar items of such Pledged
     Subsidiaries and the right to receive distributions of such Pledged
     Subsidiary's cash, other property, assets, and all options and warrants for
     the purchase of membership interests, whether now existing or hereafter
     arising, whether arising under

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     the terms of the Certificates of Formation, the Limited Liability Company
     Agreements or any of the other organizational documents (such documents
     hereinafter collectively referred to as the "Operating Agreements") of such
     Pledged Subsidiaries, or at law or in equity, or otherwise and any and all
     of the proceeds thereof (all of said membership interests, certificates,
     and warrants being hereinafter collectively referred to as the "Pledged
     Membership Interests") herewith delivered, if applicable, to the
     Administrative Agent indorsed in blank or accompanied by appropriate
     instruments of transfer duly executed in blank, and all distributions,
     cash, instruments, investment property and other property from time to time
     received, receivable or otherwise distributed in respect of, or in exchange
     for, any or all of the Pledged Membership Interests;

               (ii) Any additional membership interests in the Pledged
     Subsidiaries described in Section 1(b)(i) above from time to time acquired
     by the Pledgor in any manner, and any certificates, which, if applicable,
     shall be delivered to the Administrative Agent indorsed in blank or
     accompanied by appropriate instruments of transfer duly executed in blank,
     representing such additional membership interests or any additional
     percentage interests, shares, units, options or warrants of membership
     interests in Pledged Subsidiaries (any such additional interests shall
     constitute part of the Pledged Membership Interests, and the Administrative
     Agent is irrevocably authorized to unilaterally amend Schedule I hereto or
     any Schedule I to any applicable Pledge Supplement from time to time to
     reflect such additional interests), and all options, warrants,
     distributions, investment property, cash, instruments and other rights and
     options from time to time received, receivable or otherwise distributed in
     respect of or in exchange for any or all of such interests, and the Pledgor
     shall promptly thereafter deliver to the Administrative Agent a certificate
     duly executed by the Pledgor describing such percentage interests,
     certificates, units, options or warrants and certifying that the same have
     been duly pledged hereunder;

          (c) (i) All of the partnership interests of the Pledgor in and to the
     Pledged Subsidiaries listed on Schedule I which are partnerships now or at
     any time or times hereafter owned directly by the Pledgor (such partnership
     interests being identified on Schedule I attached hereto to or on Schedule
     I to any applicable Pledge Supplement), the property (and interests in
     property) that is owned by such Pledged Subsidiaries, all of the Pledgor's
     rights, if any, to participate in the management of such Pledged
     Subsidiaries, all rights, privileges, authority and powers of the Pledgor
     as owner or holder of its partnership interests in such Pledged
     Subsidiaries, including, but not limited to, all contract rights related
     thereto, all rights, privileges, authority and powers relating to the
     economic interests of the Pledgor as owner or holder of its partnership
     interests in such Pledged Subsidiaries, including, without limitation, all
     contract rights related thereto, all options and warrants of the Pledgor
     for the purchase of any partnership interests in such Pledged Subsidiaries,
     all documents and certificates representing or evidencing the Pledgor's
     partnership interest in such Pledged Subsidiaries, all of the Pledgor's
     interest in and to the profits and losses of such Pledged Subsidiaries and
     the Pledgor's right as a partner of such Pledged Subsidiaries to receive
     distributions of such Pledged Subsidiaries' assets, upon complete or
     partial liquidation or otherwise, all of the Pledgor's right, title and
     interest to receive payments of principal and interest on any loans and/or
     other extensions of credit made by the Pledgor or its Affiliates to such

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     Pledged Subsidiaries, all distributions, cash, instruments, investment
     property and other property from time to time received, receivable or
     otherwise distributed in respect of, or in exchange for, the Pledgor's
     partnership interests in such Pledged Subsidiaries, and any other right,
     title, interest, privilege, authority and power of the Pledgor in or
     relating to such Pledged Subsidiaries, all whether now existing or
     hereafter arising, and whether arising under any partnership agreements of
     such Pledged Subsidiaries (as the same may be amended, modified or restated
     from time to time, the "Partnership Agreements") or otherwise, or at law or
     in equity and all books and records of the Pledgor pertaining to any of the
     foregoing (all of the foregoing being referred to collectively as the
     "Pledged Partnership Interests");

               (ii) Any additional partnership interests in the Pledged
     Subsidiaries described in Section 1(c)(i) above from time to time acquired
     by the Pledgor in any manner (any such additional interests shall
     constitute part of the Pledged Partnership Interests, and the
     Administrative Agent is irrevocably authorized to unilaterally amend
     Schedule I hereto or any Schedule I to any applicable Pledge Supplement
     from time to time to reflect such additional interests), and all options,
     warrants, distributions, investment property, cash, instruments and other
     rights and options from time to time received, receivable or otherwise
     distributed in respect of or in exchange for any or all of such interests,
     and the Pledgor shall promptly thereafter deliver to the Administrative
     Agent a certificate duly executed by the Pledgor describing such percentage
     interests, options or warrants and certifying that the same have been duly
     pledged hereunder;

          (d) The property and interests in property described in Section 3
     below; and

          (e) All proceeds of the collateral described in subsections (a)
     through (d) above.

Notwithstanding the foregoing, the Pledged Collateral shall not include Equity
Interests held by the Pledgor in any of its Foreign Subsidiaries until such
pledge is required pursuant to Section 6.28(b) of the Credit Agreement, and at
no time shall any such security interests, individually or collectively, with
respect to any Foreign Subsidiary exceed 65% of the Voting Equity Interests of
such Foreign Subsidiary, regardless of whether certificates representing a
greater percentage may be delivered to the Administrative Agent.

          SECTION 2. Security for Secured Obligations. The Pledged Collateral
secures the prompt payment, performance and observance of the Secured
Obligations.

          SECTION 3. Pledged Collateral Adjustments. If, during the term of this
Pledge Agreement:

          (a) Any stock dividend, reclassification, readjustment or other change
     is declared or made in the capital structure of any of the Pledged
     Subsidiaries, or any option included within the Pledged Collateral is
     exercised, or both, or

          (b) Any subscription warrants or any other rights or options shall be
     issued in connection with the Pledged Collateral,

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then all new, substituted and additional membership or partnership interests,
certificates, shares, warrants, rights, options, investment property or other
securities, issued by reason of any of the foregoing, shall, if applicable, be
immediately delivered to and held by the Administrative Agent under the terms of
this Pledge Agreement and shall constitute Pledged Collateral hereunder;
provided, however, that nothing contained in this Section 3 shall be deemed to
permit any distribution or stock dividend, issuance of additional membership or
partnership interests or stock, warrants, rights or options, reclassification,
readjustment or other change in the capital structure of any Pledged Subsidiary
which is not expressly permitted in the Credit Agreement.

          SECTION 4. Subsequent Changes Affecting Pledged Collateral. The
Pledgor represents and warrants that it has made its own arrangements for
keeping itself informed of changes or potential changes affecting the Pledged
Collateral (including, but not limited to, rights to convert, rights to
subscribe, payment of dividends, cash distributions or other distributions,
reorganizations or other exchanges, tender offers and voting rights), and the
Pledgor agrees that neither the Administrative Agent nor any of the Holders of
Secured Obligations shall have any obligation to inform the Pledgor of any such
changes or potential changes or to take any action or omit to take any action
with respect thereto. The Administrative Agent may, after the occurrence and
during the continuance of a Default, upon notice and at its option, transfer or
register the Pledged Collateral or any part thereof into its or its nominee's
name with or without any indication that such Pledged Collateral is subject to
the security interest hereunder. In addition, the Administrative Agent may,
after the occurrence and during the continuance of a Default, exchange
certificates or instruments representing or evidencing Pledged Shares, Pledged
Membership Interests or Pledged Partnership Interests for certificates or
instruments of smaller or larger denominations.

          SECTION 5. Representations and Warranties. The Pledgor represents and
warrants as follows:

          (a) The Pledgor is the sole legal and beneficial owner of 100% of the
          issued and outstanding common stock, membership interests or
          partnership interests, as applicable, of the Pledged Subsidiaries,
          free and clear of any Lien except for the security interest created by
          this Pledge Agreement;

          (b) The Pledgor has full corporate power and authority to enter into
          this Pledge Agreement;

          (c) There are no restrictions upon the voting rights associated with,
          or upon the transfer of, any of the Pledged Collateral;

          (d) The Pledgor has the right to vote, pledge and grant a security
          interest in or otherwise transfer such Pledged Collateral free of any
          Liens, except for the pledge and security interest granted to the
          Administrative Agent hereunder;

          (e) The Pledgor owns the Pledged Collateral free and clear of any
          pledge, mortgage, hypothecation, lien, charge, encumbrance or any
          security interest therein, except for the pledge and security interest
          granted to the Administrative Agent hereunder;

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          (f) The pledge of the Pledged Collateral does not violate (1) the
          articles, by-laws, Operating Agreements or Partnership Agreements, as
          applicable, of the Pledged Subsidiaries, or any indenture, mortgage,
          bank loan or credit agreement to which the Pledgor or any of the
          Pledged Subsidiaries is a party or by which any of their respective
          properties or assets may be bound; or (2) any restriction on such
          transfer or encumbrance of such Pledged Collateral;

          (g) The Pledgor shall cause the Pledged Subsidiaries which are limited
          liability companies or limited partnerships to make a notation on
          their respective records, which notation shall indicate the security
          interest granted hereby;

          (h) The Pledgor authorizes the Administrative Agent to file financing
          statements pursuant to the UCC as the Administrative Agent may
          reasonably request to perfect the security interest granted hereby;

          (i) No authorization, approval, or other action by, and no notice to
          or filing with, any governmental authority or regulatory body is
          required either (i) for the pledge of the Pledged Collateral pursuant
          to this Pledge Agreement or for the execution, delivery or performance
          of this Pledge Agreement by the Pledgor (except for the filing of
          financing statements contemplated pursuant to Section 5(h) hereof) or
          (ii) for the exercise by the Administrative Agent of the voting or
          other rights provided for in this Pledge Agreement or the remedies in
          respect of the Pledged Collateral pursuant to this Pledge Agreement
          (except as may be required in connection with such disposition by laws
          affecting the offering and sale of securities generally);

          (j) Upon delivery of each of the certificates representing the Pledged
          Collateral, or, as applicable, the filing of financing statements
          pursuant to Section 5(h) hereof, or upon execution of a control
          agreement, the pledge of the Pledged Collateral pursuant to this
          Pledge Agreement will create a valid and perfected first priority
          security interest in the Pledged Collateral, in favor of the
          Administrative Agent for the benefit of the Administrative Agent and
          the Holders of Secured Obligations, securing the payment and
          performance of the Secured Obligations;

          (k) The Powers are duly executed and give the Administrative Agent the
          authority they purport to confer; and

          (l) The Pledgor has no obligation to make further capital
          contributions or make any other payments to the Pledged Subsidiaries
          with respect to its interest therein.

          (m) As of the date hereof, the subsidiaries listed on Schedule II
          hereto constitute all of the Pledgor's domestic subsidiaries which are
          not Pledged Subsidiaries, and none of the subsidiaries listed on
          Schedule II hereto conducts any operations, and all of the
          subsidiaries listed on Schedule II, collectively, do not have assets
          in an aggregate value in excess of $250,000.

          SECTION 6. Voting Rights. During the term of this Pledge Agreement,
and except as provided in this Section 6 below, the Pledgor shall have (i) the
right to vote the Pledged Stock, Pledged Membership Interests or Pledged
Partnership Interests on all governing

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questions in a manner not inconsistent with the terms of this Pledge Agreement
or the Loan Documents and (ii) the right to be a member or a partner of all the
Pledged Subsidiaries which are limited liability companies or partnerships,
respectively. After the occurrence and during the continuance of a Default, the
Administrative Agent or the Administrative Agent's nominee may, at the
Administrative Agent's or such nominee's option and following written notice
from the Administrative Agent to the Pledgor, (i) exercise all voting powers
pertaining to the Pledged Collateral, including the right to take action by
shareholder consent and (ii) become a member or partner of each and all of the
Pledged Subsidiaries which are limited liability companies or partnerships,
respectively, and as such (x) exercise, or direct the Pledgor as to the exercise
of all voting, consent, managerial, election and other membership rights to the
applicable Pledged Collateral and (y) exercise, or direct the Pledgor as to the
exercise of any and all rights of conversion, exchange, subscription or any
other rights, privileges or options pertaining to the applicable Pledged
Collateral, as if the Administrative Agent were the absolute owner thereof, all
without liability except to account for property actually received by it, but
the Administrative Agent shall have no duty to exercise any of the aforesaid
rights, privileges or options and shall not be responsible for any failure so to
do or delay in so doing. Such authorization shall constitute an irrevocable
voting proxy from the Pledgor to the Administrative Agent or, at the
Administrative Agent's option, to the Administrative Agent's nominee. After a
Default is cured or waived, the Pledgor will have the right to exercise the
voting and rights, powers, privileges and options that it would otherwise be
entitled to exercise pursuant to the terms of the Pledge Agreement prior to the
occurrence of any such Default.

          SECTION 7. Dividends and Other Distributions. (a) So long as no
Default has occurred and is continuing:

          (i) The Pledgor shall be entitled to receive and retain any and all
     dividends, cash distributions and interest paid in respect of the Pledged
     Collateral to the extent such distributions are not prohibited by the
     Credit Agreement, provided, however, that any and all distributions,
     dividends and interest paid or payable other than in cash with respect to,
     and instruments and other property received, receivable or otherwise
     distributed with respect to, or in exchange for, any of the Pledged
     Collateral shall be Pledged Collateral, and shall be forthwith delivered to
     the Administrative Agent to hold, for the benefit of the Administrative
     Agent and the Holders of Secured Obligations, as Pledged Collateral and
     shall, if received by the Pledgor, be received in trust for the
     Administrative Agent, for the benefit of the Administrative Agent and the
     Holders of Secured Obligations, be segregated from the other property or
     funds of the Pledgor, and be delivered immediately to the Administrative
     Agent as Pledged Collateral in the same form as so received (with any
     necessary endorsement); and

          (ii) The Administrative Agent shall execute and deliver (or cause to
     be executed and delivered) to the Pledgor all such proxies and other
     instruments as the Pledgor may reasonably request for the purpose of
     enabling the Pledgor to receive the dividends or interest payments which it
     is authorized to receive and retain pursuant to clause (i) above.

     (b) After the occurrence and during the continuance of a Default:

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          (i) All rights of the Pledgor to receive the dividends, distributions
     and interest payments which it would otherwise be authorized to receive and
     retain pursuant to Section 7(a)(i) hereof shall cease, and all such rights
     shall thereupon become vested in the Administrative Agent, for the benefit
     of the Administrative Agent and the Holders of Secured Obligations, which
     shall thereupon have the sole right to receive and hold as Pledged
     Collateral such dividends, distributions and interest payments; and

          (ii) All dividends, distributions and interest payments which are
     received by the Pledgor contrary to the provisions of clause (i) of this
     Section 7(b) shall be received in trust for the Administrative Agent, for
     the benefit of the Administrative Agent and the Holders of Secured
     Obligations, shall be segregated from other funds of the Pledgor and shall
     be paid over immediately to the Administrative Agent as Pledged Collateral
     in the same form as so received (with any necessary endorsements).

          SECTION 8. Transfers and Other Liens. The Pledgor agrees that it will
not (i) except as otherwise permitted by the Credit Agreement, sell or otherwise
dispose of, or grant any option with respect to, any of the Pledged Collateral
without the prior written consent of the Administrative Agent, or (ii) except as
otherwise permitted by the Credit Agreement, create or permit to exist any Lien
upon or with respect to any of the Pledged Collateral, except for the security
interest under this Pledge Agreement.

          SECTION 9. Remedies. (a) The Administrative Agent shall have, in
addition to any other rights given under this Pledge Agreement or by law, all of
the rights and remedies with respect to the Pledged Collateral of a secured
party under the UCC. The Administrative Agent (personally or through an agent)
is hereby authorized and empowered to transfer and register in its name or in
the name of its nominee the whole or any part of the Pledged Collateral, to
exercise all voting rights with respect thereto, to collect and receive all cash
dividends or distributions and other distributions made thereon, and to
otherwise act with respect to the Pledged Collateral as though the
Administrative Agent were the outright owner thereof (in the case of a limited
liability company, the sole member and manager thereof and, in the case of a
partnership, a partner thereof), the Pledgor hereby irrevocably constituting and
appointing the Administrative Agent as the proxy and attorney-in-fact of the
Pledgor, with full power of substitution to do so; provided, however, that the
Administrative Agent shall have no duty to exercise any such right or to
preserve the same and shall not be liable for any failure to do so or for any
delay in doing so; provided, further, however, that the Administrative Agent
agrees to exercise such proxy and powers only so long as a Default shall have
occurred and is continuing and following written notice thereof. In addition,
after the occurrence and during the continuance of a Default and following
written notice thereof, the Administrative Agent shall have such powers of sale
and other powers as may be conferred by applicable law and regulatory
requirements. With respect to the Pledged Collateral or any part thereof which
shall then be in or shall thereafter come into the possession or custody of the
Administrative Agent or which the Administrative Agent shall otherwise have the
ability to transfer under applicable law, the Administrative Agent may, in its
sole discretion, without notice except as specified below, after the occurrence
and during the continuance of a Default, sell or cause the same to be sold at
any exchange, broker's board or at public or private sale, in one or more sales
or lots, at such price as the Administrative Agent may deem best, for cash or on
credit or for future delivery, without assumption of any credit risk, and the
purchaser of any or all of the Pledged Collateral so sold

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shall thereafter own the same, absolutely free from any claim, encumbrance or
right of any kind whatsoever. The Administrative Agent and each of the Holders
of Secured Obligations may, in its own name, or in the name of a designee or
nominee, buy the Pledged Collateral at any public sale and, if permitted by
applicable law, buy the Pledged Collateral at any private sale. The Pledgor will
pay to the Administrative Agent all reasonable expenses (including, without
limitation, court costs and reasonable attorneys' and paralegals' fees and
expenses) of, or incidental to, the enforcement of any of the provisions hereof.
The Administrative Agent agrees to distribute any proceeds of the sale of the
Pledged Collateral in accordance with the Credit Agreement and the Pledgor shall
remain liable for any deficiency following the sale of the Pledged Collateral.

          (b) Unless any of the Pledged Collateral threatens to decline speedily
in value or is or becomes of a type sold on a recognized market, the
Administrative Agent will give the Pledgor reasonable notice of the time and
place of any public sale thereof, or of the time after which any private sale or
other intended disposition is to be made. Any sale of the Pledged Collateral
conducted in conformity with reasonable commercial practices of banks,
commercial finance companies, insurance companies or other financial
institutions disposing of property similar to the Pledged Collateral shall be
deemed to be commercially reasonable. Notwithstanding any provision to the
contrary contained herein, the Pledgor agrees that any requirements of
reasonable notice shall be met if such notice is received by the Pledgor as
provided in Section 21 below at least ten (10) days before the time of the sale
or disposition; provided, however, that the Administrative Agent may give any
shorter notice that is commercially reasonable under the circumstances. Any
other requirement of notice, demand or advertisement for sale is waived, to the
extent permitted by law.

          (c) In view of the fact that federal and state securities laws may
impose certain restrictions on the method by which a sale of the Pledged
Collateral may be effected after a Default, the Pledgor agrees that after the
occurrence and during the continuance of a Default, the Administrative Agent
may, from time to time, attempt to sell all or any part of the Pledged
Collateral by means of a private placement restricting the bidders and
prospective purchasers to those who are qualified and will represent and agree
that they are purchasing for investment only and not for distribution. In so
doing, the Administrative Agent may solicit offers to buy the Pledged
Collateral, or any part of it, from a limited number of investors deemed by the
Administrative Agent, in its reasonable judgment, to be financially responsible
parties who might be interested in purchasing the Pledged Collateral. If the
Administrative Agent solicits such offers from not less than four (4) such
investors, then the acceptance by the Administrative Agent of the highest offer
obtained therefrom shall be deemed to be a commercially reasonable method of
disposing of such Pledged Collateral; provided, however, that this Section does
not impose a requirement that the Administrative Agent solicit offers from four
or more investors in order for the sale to be commercially reasonable.

          SECTION 10. Administrative Agent Appointed Attorney-in-Fact. The
Pledgor hereby appoints the Administrative Agent its attorney-in-fact, coupled
with an interest, with full authority, in the name of the Pledgor or otherwise,
from time to time in the Administrative Agent's sole discretion, to take any
action and to execute any instrument which the Administrative Agent may
reasonably deem necessary or advisable to accomplish the purposes of this Pledge
Agreement, including, without limitation, to receive, endorse and collect all

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instruments made payable to the Pledgor representing any dividend, distribution,
interest payment or other distribution in respect of the Pledged Collateral or
any part thereof and to give full discharge for the same and to arrange for the
transfer of all or any part of the Pledged Collateral on the books of the
Pledged Subsidiaries to the name of the Administrative Agent or the
Administrative Agent's nominee; provided, however that the Administrative Agent
agrees to exercise such powers only so long as a Default shall have occurred and
is continuing.

          SECTION 11. Waivers. (i) The Pledgor waives presentment and demand for
payment of any of the Secured Obligations, protest and notice of dishonor or
Default with respect to any of the Secured Obligations and all other notices to
which the Pledgor might otherwise be entitled except as otherwise expressly
provided herein or in the Credit Agreement.

          (ii) The Pledgor understands and agrees that its obligations and
liabilities under this Pledge Agreement shall remain in full force and effect,
notwithstanding foreclosure of any real property securing all or any part of the
Secured Obligations by trustee sale or any other reason impairing the right of
the Pledgor, the Administrative Agent or any of the Holders of Secured
Obligations to proceed against any Pledged Subsidiary, any other guarantor or
any Pledged Subsidiary or such guarantor's property. The Pledgor agrees that all
of its obligations under this Pledge Agreement shall remain in full force and
effect without defense, offset or counterclaim of any kind, notwithstanding that
the Pledgor's rights against any Pledged Subsidiary may be impaired, destroyed
or otherwise affected by reason of any action or inaction on the part of the
Administrative Agent or any Holder of Secured Obligations. By way of example and
without limiting the foregoing, if the Administrative Agent shall release or
foreclose by private power of sale any real property that secures the Secured
Obligations, then notwithstanding that a Pledged Subsidiary may be entitled
thereby to assert a defense against such Secured Obligations (and thus also
against its obligations to the Pledgor to the extent that the Pledgor may be
subrogated to the rights of the Holders of Secured Obligations) based upon the
applicability of California Code of Civil Procedure Section 580d or other
antideficiency laws, the Pledgor nonetheless shall remain fully obligated
hereunder. The Pledgor waives, to the fullest extent permitted by law, all
defenses, protections and benefits of Sections 580a, 580b, 580d and 726 of the
California Code of Civil Procedure, and all judicial decisions construing or
pertaining to the same, and all rules and principles of like kind or similar
effect (including, without limitation, the so-called one-action rule, the
one-form-of-action rule and the security-first rule), in each case as applicable
to or in favor of the Pledgor, any applicable Pledged Subsidiary or otherwise.
In addition, the Pledgor hereby waives, to the fullest extent permitted by law,
without limiting the generality of the foregoing or any other provision hereof,
all rights and benefit under California Civil Code Sections 2810, 2819, 2839,
2845, 2849, 2850, 2899, and 3433 (or any similar law in California or in any
other jurisdiction).

          (iii) The Pledgor hereby expressly waives, to the fullest extent
permitted by law, the benefits of Section 2815 of the California Civil Code (or
any similar law in California or in any other jurisdiction) purporting to allow
a guarantor or pledgor to revoke a continuing guaranty or pledge with respect to
any transactions occurring after the date of the guaranty or pledge.

          SECTION 12. Term. This Pledge Agreement shall remain in full force and
effect until the Secured Obligations have been fully and indefeasibly paid in
cash and the Credit Agreement has terminated pursuant to its terms. Upon the
termination of this Pledge Agreement

                                       10

<PAGE>

as provided above (other than as a result of the sale of the Pledged
Collateral), the Administrative Agent will release the security interest created
hereunder and, if it then has possession of the Pledged Stock, will deliver the
Pledged Stock and the Powers to the Pledgor.

          SECTION 13. Definitions. Unless otherwise defined herein, terms
defined in the Credit Agreement are used herein as therein defined (and, with
respect to such terms, the singular shall include the plural and vice versa and
any gender shall include any other gender as the context may require), and the
following term shall have the following meaning.

          "UCC" shall mean the Uniform Commercial Code as the same may, from
time to time, be in effect in the State of Illinois, as amended or supplemented
from time to time; provided, however, in the event that, by reason of mandatory
provisions of law, any or all of the attachment, perfection or priority of the
Agent's and the Holders of Secured Obligations' security interest in any
Collateral is governed by the Uniform Commercial Code as in effect in a
jurisdiction other than the State of Illinois, the term "UCC" shall mean the
Uniform Commercial Code as in effect in such other jurisdiction for purposes of
the provisions hereof relating to such attachment, perfection or priority and
for purposes of definitions related to such provisions. Any and all terms used
in this Agreement which are defined in the UCC shall be construed and defined in
accordance with the meaning and definition ascribed to such terms under the UCC,
unless otherwise defined herein.

          SECTION 14. Successors and Assigns. This Pledge Agreement shall be
binding upon and inure to the benefit of the Pledgor, the Administrative Agent,
for the benefit of itself and the Holders of Secured Obligations, and their
respective successors and assigns. The Pledgor's successors and assigns shall
include, without limitation, a receiver, trustee or debtor-in-possession of or
for the Pledgor.

          SECTION 15. GOVERNING LAW. ANY DISPUTE BETWEEN THE PLEDGOR AND THE
ADMINISTRATIVE AGENT, ANY HOLDER OF SECURED OBLIGATIONS OR ANY INDEMNITEE
ARISING OUT OF, CONNECTED WITH, RELATED TO, OR INCIDENTAL TO THE RELATIONSHIP
ESTABLISHED BETWEEN THEM IN CONNECTION WITH, THIS PLEDGE AGREEMENT OR ANY OF THE
OTHER LOAN DOCUMENTS, AND WHETHER ARISING IN CONTRACT, TORT, EQUITY, OR
OTHERWISE, SHALL BE RESOLVED IN ACCORDANCE WITH THE INTERNAL LAWS (INCLUDING,
WITHOUT LIMITATION, 735 ILCS SECTION 105/5-1 ET SEQ, BUT OTHERWISE WITHOUT
REGARD TO THE CONFLICTS OF LAWS PROVISIONS) OF THE STATE OF ILLINOIS (EXCEPT TO
THE EXTENT THAT THE UCC PROVIDES FOR THE APPLICATION OF LAWS OF ANOTHER STATE),
BUT GIVING EFFECT TO FEDERAL LAWS APPLICABLE TO NATIONAL BANKS.

          SECTION 16. CONSENT TO JURISDICTION; SERVICE OF PROCESS; JURY TRIAL.

          (A) CONSENT TO JURISDICTION. THE PLEDGOR HEREBY IRREVOCABLY SUBMITS TO
THE NON-EXCLUSIVE JURISDICTION OF ANY UNITED STATES FEDERAL OR ILLINOIS STATE
COURT SITTING IN CHICAGO, ILLINOIS IN ANY ACTION OR PROCEEDING ARISING OUT OF OR
RELATING TO THIS

                                       11

<PAGE>

AGREEMENT OR ANY LOAN DOCUMENT AND THE PLEDGOR HEREBY IRREVOCABLY AGREES THAT
ALL CLAIMS IN RESPECT OF SUCH ACTION OR PROCEEDING MAY BE HEARD AND DETERMINED
IN ANY SUCH COURT AND IRREVOCABLY WAIVES ANY OBJECTION IT MAY NOW OR HEREAFTER
HAVE AS TO THE VENUE OF ANY SUCH SUIT, ACTION OR PROCEEDING BROUGHT IN SUCH A
COURT OR THAT SUCH COURT IS AN INCONVENIENT FORUM. NOTHING HEREIN SHALL LIMIT
THE RIGHT OF THE ADMINISTRATIVE AGENT OR ANY LENDER TO BRING PROCEEDINGS AGAINST
THE PLEDGOR IN THE COURTS OF ANY OTHER JURISDICTION.

          (B) OTHER JURISDICTIONS. THE PLEDGOR AGREES THAT THE ADMINISTRATIVE
AGENT, ANY LENDER OR ANY HOLDER OF SECURED OBLIGATIONS SHALL HAVE THE RIGHT TO
PROCEED AGAINST THE PLEDGOR OR ITS PROPERTY IN A COURT IN ANY LOCATION TO ENABLE
SUCH PERSON TO (1) OBTAIN PERSONAL JURISDICTION OVER THE PLEDGOR OR (2) REALIZE
ON THE COLLATERAL OR ANY OTHER SECURITY FOR THE OBLIGATIONS OR TO ENFORCE A
JUDGMENT OR OTHER COURT ORDER ENTERED IN FAVOR OF SUCH PERSON. THE PLEDGOR
WAIVES ANY OBJECTION THAT IT MAY HAVE TO THE LOCATION OF THE COURT IN WHICH SUCH
PERSON HAS COMMENCED A PROCEEDING DESCRIBED IN THIS SUBSECTION.

          (C) SERVICE OF PROCESS; VENUE. THE PLEDGOR WAIVES PERSONAL SERVICE OF
ANY PROCESS UPON IT AND IRREVOCABLY CONSENTS TO THE SERVICE OF PROCESS OF ANY
WRITS, PROCESS OR SUMMONSES IN ANY SUIT, ACTION OR PROCEEDING BY THE MAILING
THEREOF BY THE ADMINISTRATIVE AGENT OR ANY HOLDER OF SECURED OBLIGATIONS BY
REGISTERED OR CERTIFIED MAIL, POSTAGE PREPAID, TO THE PLEDGOR ADDRESSED AS
PROVIDED HEREIN. NOTHING HEREIN SHALL IN ANY WAY BE DEEMED TO LIMIT THE ABILITY
OF THE ADMINISTRATIVE AGENT OR ANY HOLDER OF SECURED OBLIGATIONS TO SERVE ANY
SUCH WRITS, PROCESS OR SUMMONSES IN ANY OTHER MANNER PERMITTED BY APPLICABLE
LAW. THE PLEDGOR IRREVOCABLY WAIVES ANY OBJECTION (INCLUDING, WITHOUT
LIMITATION, ANY OBJECTION OF THE LAYING OF VENUE OR BASED ON THE GROUNDS OF
FORUM NON CONVENIENS) WHICH IT MAY NOW OR HEREAFTER HAVE TO THE BRINGING OF ANY
SUCH ACTION OR PROCEEDING WITH RESPECT TO THIS PLEDGE AGREEMENT OR ANY OTHER
INSTRUMENT, DOCUMENT OR AGREEMENT EXECUTED OR DELIVERED IN CONNECTION HEREWITH
IN ANY JURISDICTION SET FORTH ABOVE.

          (D) WAIVER OF JURY TRIAL. EACH OF THE PARTIES HERETO HEREBY WAIVES
TRIAL BY JURY IN ANY JUDICIAL PROCEEDING INVOLVING, DIRECTLY OR INDIRECTLY, ANY
MATTER (WHETHER SOUNDING IN TORT, CONTRACT OR OTHERWISE) IN ANY WAY ARISING OUT
OF, RELATED TO, OR CONNECTED WITH THIS AGREEMENT OR ANY LOAN DOCUMENT OR THE
RELATIONSHIP ESTABLISHED THEREUNDER.

                                       12

<PAGE>

          (E) WAIVER OF BOND. PLEDGOR WAIVES THE POSTING OF ANY BOND OTHERWISE
REQUIRED OF ANY PARTY HERETO IN CONNECTION WITH ANY JUDICIAL PROCESS OR
PROCEEDING TO REALIZE ON THE COLLATERAL OR ANY OTHER SECURITY FOR THE SECURED
OBLIGATIONS OR TO ENFORCE ANY JUDGMENT OR OTHER COURT ORDER ENTERED IN FAVOR OF
SUCH PARTY, OR TO ENFORCE BY SPECIFIC PERFORMANCE, TEMPORARY RESTRAINING ORDER,
PRELIMINARY OR PERMANENT INJUNCTION, THIS AGREEMENT.

          (F) ADVICE OF COUNSEL. EACH OF THE PARTIES REPRESENTS TO EACH OTHER
PARTY HERETO THAT IT HAS DISCUSSED THIS AGREEMENT AND, SPECIFICALLY, THE
PROVISIONS OF THIS SECTION 16, WITH ITS COUNSEL.

          SECTION 17. No Strict Construction. The parties hereto have
participated jointly in the negotiation and drafting of this Pledge Agreement.
In the event an ambiguity or question of intent or interpretation arises, this
Pledge Agreement shall be construed as if drafted jointly by the parties hereto
and no presumption or burden of proof shall arise favoring or disfavoring any
party by virtue of the authorship of any provisions of this Pledge Agreement.

          SECTION 18. Severability. Whenever possible, each provision of this
Pledge Agreement shall be interpreted in such manner as to be effective and
valid under applicable law, but, if any provision of this Pledge Agreement shall
be held to be prohibited or invalid under applicable law, such provision shall
be ineffective only to the extent of such prohibition or invalidity, without
invalidating the remainder of such provision or the remaining provisions of this
Pledge Agreement.

          SECTION 19. Further Assurances. The Pledgor agrees that it will
cooperate with the Administrative Agent and will execute and deliver, or cause
to be executed and delivered, all such other stock powers, proxies, instruments
and documents, and will take all such other actions, including, without
limitation, the execution and filing of financing statements, as the
Administrative Agent may reasonably request from time to time in order to carry
out the provisions and purposes of this Pledge Agreement.

          SECTION 20. The Administrative Agent's Duty of Care. The
Administrative Agent shall not be liable for any acts, omissions, errors of
judgment or mistakes of fact or law including, without limitation, acts,
omissions, errors or mistakes with respect to the Pledged Collateral, except for
those arising out of or in connection with the Administrative Agent's (or the
Administrative Agent's officers', directors', affiliates', agents' or
employees') (i) gross negligence or willful misconduct, or (ii) failure to use
reasonable care with respect to the safe custody of the Pledged Collateral in
the Administrative Agent's possession. Without limiting the generality of the
foregoing, the Administrative Agent shall be under no obligation to take any
steps necessary to preserve rights in the Pledged Collateral against any other
parties but may do so at its option. All expenses incurred in connection
therewith shall be for the sole account of the Pledgor, and shall constitute
part of the Secured Obligations secured hereby.

          SECTION 21. Notices. All notices and other communications provided for
hereunder shall be delivered in the manner set forth in Section 13.1 of the
Credit Agreement.

                                       13

<PAGE>

          SECTION 22. Amendments, Waivers and Consents. No amendment or waiver
of any provision of this Pledge Agreement nor consent to any departure by the
Pledgor herefrom, shall in any event be effective unless the same shall be in
writing and signed by the Administrative Agent pursuant to the terms of the
Credit Agreement, and then such amendment, waiver or consent shall be effective
only in the specific instance and for the specific purpose for which given.

          SECTION 23. Section Headings. The section headings herein are for
convenience of reference only, and shall not affect in any way the
interpretation of any of the provisions hereof.

          SECTION 24. Execution in Counterparts. This Pledge Agreement may be
executed in any number of counterparts, each of which shall be an original, but
all of which shall together constitute one and the same agreement.

          SECTION 25. Merger. This Pledge Agreement represents the final
agreement of the Pledgor with respect to the matters contained herein and may
not be contradicted by evidence of prior or contemporaneous agreements, or
subsequent oral agreements, between the Pledgor and the Administrative Agent or
any Holder of Secured Obligations.

                  [Remainder of page left intentionally blank.]

                                       14

<PAGE>

          IN WITNESS WHEREOF, the Pledgor and the Administrative Agent have
executed this Pledge Agreement as of the date set forth above.

                                       BIO-RAD LABORATORIES, INC.


                                       By: /s/ Ronald W. Hutton
                                           -------------------------------------
                                           Name: Ronald W. Hutton
                                           Title: Treasurer


                                       BANK ONE, NA, as agent for itself and the
                                       Holders of Secured Obligations


                                       By: /s/ Dana Jurgens
                                           -------------------------------------
                                           Name: Dana Jurgens
                                           Title: Director

                       Signature Page to Pledge Agreement

<PAGE>

                                 ACKNOWLEDGMENT

          Each of the undersigned hereby acknowledges receipt of a copy of the
foregoing Pledge Agreement, agrees promptly to note on its books the security
interests granted under such Pledge Agreement, agrees that after the occurrence
and during the continuance of a Default it will comply with instructions
originated by the Administrative Agent without further consent by the Pledgor
and waives any rights or requirement at any time hereafter to receive a copy of
such Pledge Agreement in connection with the registration of any Pledged
Collateral in the name of the Administrative Agent or its nominee or the
exercise of voting rights by the Administrative Agent or its nominee.

BIO-RAD LABORATORIES (ISRAEL), INC.          BIO-RAD PACIFIC LIMITED


By: /s/ Sanford S. Wadler                    By: /s/ Sanford S. Wadler
    -------------------------------              -------------------------------
    Name: Sanford S. Wadler                      Name: Sanford S. Wadler
    Title: Secretary                             Title: Assistant Secretary


BIO-METRICS, LIMITED                         BIO-RAD EXPORT INC.


By: /s/ Sanford S. Wadler                    By: /s/ Sanford S. Wadler
    -------------------------------              -------------------------------
    Name: Sanford S. Wadler                      Name: Sanford S. Wadler
    Title: Assistant Secretary                   Title: Assistant Secretary


INTERNATIONAL MARKETING
VENTURES, LTD.


By: /s/ Ashok Shah
    -------------------------------
    Name: Ashok Shah
    Title: President

                       Acknowledgment to Pledge Agreement

<PAGE>

                                    EXHIBIT A
                                       to
                                PLEDGE AGREEMENT
                          dated as of September 9, 2003

                            FORM OF PLEDGE SUPPLEMENT

     Reference is hereby made to the Pledge Agreement (the "Pledge Agreement")
dated as of the 9th day of September, 2003, by and between Bio-Rad Laboratories,
Inc. (the "Pledgor") and Bank One, N.A. (Main Office Chicago), as contractual
representative (the "Administrative Agent"), whereby the Pledgor has pledged
certain capital stock, membership interests and partnership interests, as
applicable, of certain of its Subsidiaries as collateral to the Administrative
Agent, for the ratable benefit of the Holders of Secured Obligations, as more
fully described in the Pledge Agreement. This Supplement is a "Pledge
Supplement" as defined in the Pledge Agreement and is, together with the
acknowledgments, certificates and Powers delivered herewith, subject in all
respects to the terms and provisions of the Pledge Agreement. Capitalized terms
used herein and not defined herein shall have the meanings given to them in the
Pledge Agreement.

     By its execution below, the Pledgor hereby agrees that (i) the [capital
stock of the corporation(s)] [membership interests of the limited liability
company(s)] [partnership interests of the partnership(s)] listed on the Schedule
I hereto shall be pledged to the Administrative Agent as additional collateral
pursuant to Section 1[(a)(b)(c)](ii) of the Pledge Agreement, (ii) such property
shall be considered [Pledged Stock] [Pledged Membership Interests] [Pledged
Partnership Interests] under the Pledge Agreement and be a part of the Pledged
Collateral pursuant to Section 1 of the Pledge Agreement, and (iii) each such
[corporation] [limited liability company] [partnership] listed on Schedule I
hereto shall be considered a Pledged Subsidiary for purposes of the Pledge
Agreement.

     By its execution below, the Pledgor represents and warrants that it has
full corporate power and authority to execute this Pledge Supplement and that
the representations and warranties contained in Section 5 of the Pledge
Agreement are true and correct in all respects as of the date hereof and after
taking into account the pledge of the additional [Pledged Stock] [Pledged
Membership Interests] [Pledged Partnership Interests] relating hereto.

<PAGE>

     IN WITNESS WHEREOF, the Pledgor has executed and delivered this Pledge
Supplement to the Pledge Agreement as of this      day of             ,       .
                                              ----        ------------  ------

     BIO-RAD LABORATORIES, INC.


     By:
         ----------------------
         Name:
         Title:

<PAGE>

                                     Schedule I
                                         to
                                 Pledge Supplement
                          Additional Pledged Capital Stock

<TABLE>
<CAPTION>
                                                   Shares of Capital Stock owned by
            Name              Certificate Number      Pledgor Subject to Pledge
---------------------------   ------------------   --------------------------------
<S>                               <C>                         <C>
[Name of Additional Pledged
Subsidiary]
                                  [________]                  [________]
</TABLE>

                          Pledged Membership Interests

                                                    Percentage of Membership
                                                   Interest owned by Pledgor
            Name              Certificate Number       subject to Pledge
---------------------------   ------------------   -------------------------
[Name of Additional Pledged
Subsidiary]                       [________]                  [________]

                          Pledged Partnership Interests

                                                   Percentage of Partnership
                                                   Interest owned by Pledgor
            Name              Certificate Number       subject to Pledge
---------------------------   ------------------   -------------------------
[Name of Additional Pledged
 Subsidiary]                      [________]              [________]

<PAGE>

                                 ACKNOWLEDGMENT
                                       TO
                                PLEDGE SUPPLEMENT

     The undersigned hereby acknowledges receipt of a copy of the foregoing
Pledge Supplement together with a copy of the Pledge Agreement, agrees promptly
to note on its books the security interests granted under such Pledge Agreement,
agrees that after the occurrence and during the continuance of a Default it will
comply with instructions originated by the Administrative Agent without further
consent by the Pledgor and waives any rights or requirement at any time
hereafter to receive a copy of such Pledge Agreement in connection with the
registration of any Pledged Collateral in the name of the Administrative Agent
or its nominee or the exercise of voting rights by the Administrative Agent or
its nominee.

                                                  [NAME[S] OF ADDITIONAL PLEDGED
                                                  SUBSIDIARY[IES]]


                                                  By:
                                                     ---------------------------
                                                     Name:
                                                     Title:

<PAGE>

                                    EXHIBIT B
                                       to
                                PLEDGE AGREEMENT
                          dated as of September 9, 2003

                               FORM OF STOCK POWER

          FOR VALUE RECEIVED, the undersigned does hereby sell, assign and

transfer to                                     Shares of Common Stock of
            -----------------------------------
            , a            corporation, represented by Certificate No.    (the
------------    ----------                                             --
"Stock"), standing in the name of the undersigned on the books of said
corporation and does hereby irrevocably constitute and appoint
                                                               -----------------
                                    as the undersigned's true and lawful
-----------------------------------
attorney, for it and in its name and stead, to sell, assign and transfer all or
any of the Stock, and for that purpose to make and execute all necessary acts of
assignment and transfer thereof; and to substitute one or more persons with like
full power, hereby ratifying and confirming all that said attorney or substitute
or substitutes shall lawfully do by virtue hereof.

Dated:
       ---------------

                                               BIO-RAD LABORATORIES, INC.


                                               By:
                                                   -----------------------------
                                                   Name:
                                                   Title: