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                                                                   EXHIBIT 10.15

                      FISHER SCIENTIFIC INTERNATIONAL INC.
                                 FIRST AMENDMENT
                               TO CREDIT AGREEMENT

            This FIRST AMENDMENT TO CREDIT AGREEMENT (this "Amendment") is dated
as of December 29, 2004 and entered into by and among Fisher Scientific
International Inc., a Delaware corporation (the "Borrower"), the financial
institutions listed herein (the "Lenders"), and Bank of America, N.A., as
Administrative Agent (in such capacity, the "Administrative Agent"), Banc of
America Securities LLC, as Sole Lead Arranger and Sole Book Manager, and, for
purposes of Section 4 hereof, Fisher Scientific Company L.L.C., Fisher Clinical
Services Inc., Fisher Scientific Worldwide, Inc., HyClone Laboratories, Inc. and
Apogent Technologies Inc. (collectively, the "Guarantors"), and is made with
reference to that certain Credit Agreement, dated as of August 2, 2004, by and
among the Borrower, the lenders from time to time party thereto, Bank of
America, N.A., as Administrative Agent and Swing Line Lender, and certain other
financial institutions party thereto (the "Credit Agreement"). Capitalized terms
used herein without definition shall have the same meanings herein as set forth
in the Credit Agreement.

                                    RECITALS

            WHEREAS, the Borrower and the Lenders desire to amend the Credit
Agreement to (i) change the definition of "Applicable Rate" as set forth herein
and (ii) extend to December 31, 2005 the date on which the Tranche A-2 Term Loan
Commitments shall expire;

            NOW, THEREFORE, in consideration of the premises and the agreements,
provisions and covenants herein contained, the parties hereto agree as follows:

            SECTION 1. AMENDMENTS TO THE CREDIT AGREEMENT

            1.1 AMENDMENTS TO SECTION 1: DEFINITIONS.

            Section 1.01 of the Credit Agreement is hereby amended by deleting
the definition of "Applicable Rate" therefrom in its entirety and substituting
the following therefor:

            "Applicable Rate" means, from time to time, the following
      percentages per annum, based upon the Applicable Debt Rating as set forth
      below:

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                                 APPLICABLE RATE

<TABLE>
<CAPTION>
LEVEL       APPLICABLE DEBT RATING        BASE RATE LOANS  EURODOLLAR RATE LOANS  LETTER OF CREDIT FEE  COMMITMENT FEE
<S>    <C>                                <C>              <C>                    <C>                   <C>
I      Higher than BBB or Baa2                 0.00%              0.625%                0.625%              0.175%

II     BBB or Baa2                             0.00%               0.75%                 0.75%               0.20%

III    BBB- or Baa3                            0.00%               1.00%                 1.00%               0.25%

IV     BB+ or Ba1                              0.25%               1.25%                 1.25%               0.30%

V      Lower than BB+ or Ba1, or unrated       0.50%               1.50%                 1.50%              0.375%
</TABLE>

      ; provided, however, that until the earlier of (a) the delivery of the
      financial statements for the second fiscal quarter ending after the
      Closing Date and (b) the date that the financial statements for the second
      fiscal quarter ending after the Closing Date are required to be delivered
      pursuant to Section 6.01, the Applicable Rate shall be determined based
      upon Level III above. Thereafter, each change in the Applicable Rate
      resulting from a change in the Applicable Debt Rating shall become
      effective on the date of the public announcement thereof. Any adjustment
      in the Applicable Rate shall apply to existing Eurodollar Rate Loans as
      well as any new Eurodollar Rate Loans."

            1.2 AMENDMENTS TO SECTION 2: COMMITMENTS AND CREDIT EXTENSIONS.

            A. Section 2.01(b) of the Credit Agreement is hereby amended by
deleting it in its entirety and substituting the following therefor:

            "Each Lender that has a Tranche A-2 Term Loan Commitment severally
      agrees to lend to the Borrower, on any Business Day after the conditions
      set forth in Section 4.03 have been satisfied through and including
      December 31, 2005, an amount not exceeding its Tranche A-2 Term Loan
      Commitment. The aggregate amount of the Tranche A-2 Term Loan Commitments
      is $300,000,000. Each Lender's Tranche A-2 Term Loan Commitment shall
      expire immediately and without further action on December 31, 2005 if the
      Tranche A-2 Term Loans are not made on or before that date. The Borrower
      may make only one borrowing under the Tranche A-2 Term Loan Commitments.
      Amounts borrowed under this Section 2.01(b) and subsequently repaid or
      prepaid may not be reborrowed. Tranche A-2 Term Loans may be Base Rate
      Loans or Eurodollar Rate Loans, as further provided herein."

            B. Section 2.10(b) of the Credit Agreement is hereby amended by
deleting the language preceding the table in its entirety and substituting the
following therefor:

            "The Borrower shall make principal payments on the Tranche A-2 Term
      Loans in installments on the dates and in amounts corresponding to the
      percentages of the aggregate outstanding principal amount of Tranche A-2
      Term Loans (as of the Funding Date of the Tranche A-2 Term Loans) as of
      each such date set forth below; provided, however, that in the event that
      the Funding Date of the Tranche A-2 Term Loans occurs after December 31,
      2004, any amounts scheduled to be repaid prior to the last day of the

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      first full fiscal quarter following such Funding Date shall be due on the
      Tranche A-2 Term Loan Maturity Date:"

            C. Section 2.12(b) of the Credit Agreement is hereby amended by
deleting the reference to "0.375%" contained therein and substituting "0.25%"
therefor and by deleting the reference to "December 31, 2004" contained in
clause (ii) thereof and substituting "December 31, 2005" therefor.

            D. Section 2.12(b) of the Credit Agreement is hereby further amended
by deleting the second to last sentence in its entirety and substituting the
following therefor:

            "The ticking fee shall be due and payable quarterly in arrears on
      the first Business Day after the end of each March, June, September and
      December, commencing with the first such date to occur after the Closing
      Date, and on the earlier of (A) the Funding Date of the Tranche A-2 Term
      Loans or (B) the first Business Day after December 31, 2005."

            SECTION 2. CONDITIONS TO EFFECTIVENESS

            Section 1 of this Amendment shall become effective only upon the
satisfaction of all of the following conditions precedent (the date of
satisfaction of such conditions being referred to herein as the "First Amendment
Effective Date"):

            A. LOAN PARTY DOCUMENTS. The Administrative Agent's receipt of the
following, each of which shall be originals or facsimiles (followed promptly by
originals) unless otherwise specified, each properly executed by a Responsible
Officer of the applicable Loan Party, each dated the First Amendment Effective
Date and each in form and substance satisfactory to the Administrative Agent and
each of the Lenders:

            (i) A certificate, dated as of the First Amendment Effective Date,
      of the Borrower's corporate secretary or an assistant secretary,
      certifying that there have been no changes in the Borrower's Organization
      Documents from the form of Organization Documents previously delivered to
      the Lenders;

            (ii) Resolutions of the Borrower's Board of Directors approving and
      authorizing the execution, delivery, and performance of this Amendment,
      certified as of the First Amendment Effective Date by its corporate
      secretary or an assistant secretary as being in full force and effect
      without modification or amendment;

            (iii) Signature and incumbency certificates of its officers
      executing this Amendment; and

            (iv) Copies of this Amendment executed by each Loan Party.

            B. LENDERS. The Administrative Agent shall have received copies of
this Amendment executed by the Required Lenders and each Lender with Tranche A-1
Term Loan Exposure, Tranche A-2 Term Loan Exposure or Revolving Loan Exposure.

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            C. FEES. The Borrower shall have paid to the Administrative Agent,
for ratable distribution to each Lender with Tranche A-2 Term Loan Exposure, an
upfront fee equal to 0.125% of the sum of each such Lender's Tranche A-2 Term
Loan Exposure.

            D. COMPLETION OF PROCEEDINGS. On or before the First Amendment
Effective Date, the Administrative Agent and its counsel shall have received all
counterpart originals or certified copies of such documents as the
Administrative Agent may reasonably request.

            SECTION 3. REPRESENTATIONS AND WARRANTIES

            In order to induce the Lenders to enter into this Amendment and to
amend the Credit Agreement in the manner provided herein, the Borrower
represents and warrants to each Lender that the following statements are true,
correct and complete:

            A. CORPORATE POWER AND AUTHORITY. The Borrower has all requisite
power and authority to execute, deliver and perform its obligations under this
Amendment.

            B. AUTHORIZATION; NO CONTRAVENTION. The execution, delivery and
performance of this Amendment have been duly authorized by all necessary
corporate or other organizational action, and do not and will not (i) contravene
the terms of any of the Organization Documents of the Borrower or any Guarantor;
(ii) conflict with or result in any breach or contravention of, or the creation
of any Lien (other than the creation of Liens under any of the Loan Documents in
favor of the Administrative Agent on behalf of the Lenders) under, (a) any
Contractual Obligation to which the Borrower or any Guarantor is a party or (b)
any material order, injunction, writ or decree of any Governmental Authority to
which the Borrower, any Guarantor or the property of the Borrower or any
Guarantor is subject; or (iii) violate any Law in any material respect.

            C. GOVERNMENTAL AUTHORIZATION; OTHER CONSENTS. No material approval,
consent, exemption, authorization, or other material action by, or material
notice to, or material filing with, any Governmental Authority or any other
Person that has not been obtained or made is necessary or required in connection
with the execution, delivery or performance by, or enforceability against, the
Borrower or any Guarantor of this Amendment.

            D. BINDING EFFECT. This Amendment has been duly executed and
delivered by the Borrower and each Guarantor. This Amendment constitutes a
legal, valid and binding obligation of the Borrower and each Guarantor,
enforceable against such Person in accordance with its terms, subject to
applicable bankruptcy, insolvency, reorganization, moratorium or other laws
affecting creditors' rights generally and subject to general principles of
equity, regardless of whether considered in a proceeding in equity or at law.

            E. INCORPORATION OF REPRESENTATIONS AND WARRANTIES FROM CREDIT
AGREEMENT. The representations and warranties contained in Article V of the
Credit Agreement are and will be true, correct and complete in all material
respects on and as of the First Amendment Effective Date (after giving effect to
the First Amendment) to the same extent as though made on and as of that date,
except to the extent such representations and warranties

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specifically relate to an earlier date, in which case they were true, correct
and complete in all material respects on and as of such earlier date, and except
that the representations and warranties contained in subsections (a) and (b) of
Section 5.05 of the Credit Agreement shall be deemed to refer to the most recent
statements furnished pursuant to clauses (a) and (b), respectively, of Section
6.01 of the Credit Agreement.

            F. ABSENCE OF DEFAULT. No Default has occurred and is continuing or
would result from the consummation of the transactions contemplated by this
Amendment.

            SECTION 4. ACKNOWLEDGEMENT AND CONSENT

            Each Guarantor hereby acknowledges and agrees that any of the
ancillary, Guaranty and Collateral Documents (each, a "Credit Support Document")
to which it is a party or otherwise bound shall continue in full force and
effect and that all of its obligations thereunder shall be valid and enforceable
and shall not be impaired or limited by the execution or effectiveness of this
Amendment. Each Guarantor represents and warrants that all representations and
warranties contained in the Credit Agreement as amended by this Amendment (the
"Amended Agreement") and the Credit Support Documents to which it is a party or
otherwise bound are true, correct and complete in all material respects on and
as of the First Amendment Effective Date to the same extent as though made on
and as of that date, except to the extent such representations and warranties
specifically relate to an earlier date, in which case they were true, correct
and complete in all material respects on and as of such earlier date.

            Each Guarantor acknowledges and agrees that (i) notwithstanding the
conditions to effectiveness set forth in this Amendment, such Guarantor is not
required by the terms of the Credit Agreement or any other Loan Document to
consent to the amendments to the Credit Agreement effected pursuant to this
Amendment and (ii) nothing in the Credit Agreement, this Amendment or any other
Loan Document shall be deemed to require the consent of such Guarantor to any
future amendments to the Credit Agreement.

            SECTION 5. MISCELLANEOUS

            A. REFERENCE TO AND EFFECT ON THE CREDIT AGREEMENT AND THE OTHER
LOAN DOCUMENTS.

            (i) On and after the First Amendment Effective Date, each reference
      in the Credit Agreement to "this Agreement", "hereunder", "hereof",
      "herein" or words of like import referring to the Credit Agreement, and
      each reference in the other Loan Documents to the "Credit Agreement",
      "thereunder", "thereof" or words of like import referring to the Credit
      Agreement shall mean and be a reference to the Amended Agreement.

            (ii) Except as specifically amended by this Amendment, the Credit
      Agreement and the other Loan Documents shall remain in full force and
      effect and are hereby ratified and confirmed.

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            (iii) The execution, delivery and performance of this Amendment
      shall not, except as expressly provided herein, constitute a waiver of any
      provision of, or operate as a waiver of any right, power or remedy of the
      Administrative Agent or any Lender under, the Credit Agreement or any of
      the other Loan Documents.

            B. FEES AND EXPENSES. The Borrower acknowledges that all costs, fees
and expenses as described in Section 10.04 of the Credit Agreement incurred by
the Administrative Agent and its counsel with respect to this Amendment and the
documents and transactions contemplated hereby shall be for the account of the
Borrower.

            C. HEADINGS. Section and subsection headings in this Amendment are
included herein for convenience of reference only and shall not constitute a
part of this Amendment for any other purpose or be given any substantive effect.

            D. APPLICABLE LAW. THIS AMENDMENT AND THE RIGHTS AND OBLIGATIONS OF
THE PARTIES HEREUNDER SHALL BE GOVERNED BY, AND SHALL BE CONSTRUED IN ACCORDANCE
WITH, THE LAW OF THE STATE OF NEW YORK.

            E. COUNTERPARTS; EFFECTIVENESS. This Amendment may be executed in
any one or more counterparts, each of which shall be deemed an original, but all
of which together shall constitute one and the same instrument.

                  [Remainder of page intentionally left blank]

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            IN WITNESS WHEREOF, the parties hereto have caused this Amendment to
be duly executed and delivered by their respective officers thereunto duly
authorized as of the date first written above.

                                FISHER SCIENTIFIC INTERNATIONAL INC.

                                By: ________________________________
                                Name: ______________________________
                                Title: _____________________________

                                FISHER SCIENTIFIC COMPANY L.L.C.

                                By: ________________________________
                                Name: ______________________________
                                Title: _____________________________

                                FISHER CLINICAL SERVICES INC.

                                By: ________________________________
                                Name: ______________________________
                                Title: _____________________________

                                FISHER SCIENTIFIC WORLDWIDE INC.

                                By: ________________________________
                                Name: ______________________________
                                Title: _____________________________

                                HYCLONE LABORATORIES, INC.

                                By: ________________________________
                                Name: ______________________________
                                Title: _____________________________

                                APOGENT TECHNOLOGIES INC.

                                By: ________________________________
                                Name: ______________________________
                                Title: _____________________________

                                      First Amendment to Fisher Credit Agreement

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                                BANK OF AMERICA, N.A., as Administrative
                                Agent and as a Lender

                                By: ________________________________
                                Name: ______________________________
                                Title: _____________________________

                                      First Amendment to Fisher Credit Agreement

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                                BANC OF AMERICA SECURITIES, as Sole
                                Lead Arranger and Sole Book Manager

                                By: ________________________________
                                Name: ______________________________
                                Title: _____________________________

                                      First Amendment to Fisher Credit Agreement