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Exhibit 10.327

AMENDMENT NO. 5 TO
AGREEMENT

        This Amendment No. 5 ("Amendment No. 5") is entered into effective as of
January 1, 2004 (the "Amendment Effective Date"), pursuant to and amending that
certain Agreement between Gen-Probe Incorporated, a Delaware corporation
("Gen-Probe") and Chiron Corporation, a Delaware corporation ("Chiron").
Capitalized terms used but not defined herein shall have the meanings set forth
in the Agreement.

Recitals

        A.    The parties entered into the Agreement as of June 11, 1998
pursuant to which, among other things, the parties described their respective
rights and obligations with respect to the development, manufacture, marketing
and distribution of Products in the Blood Screening and Clinical Diagnostic
Fields.

        B.    The Agreement was been previously amended and supplemented by
further written agreements of the parties.

        C.    Subsequent to the execution of the Agreement, Chiron assigned its
rights and obligations with respect to Clinical Diagnostic Products to Chiron
Diagnostics Corporation ("CDC"), now wholly owned by Bayer Corporation (CDC and
Bayer Corporation being collectively referred to as "Bayer"). Chiron retained
all rights and obligations under the Agreement with respect to Blood Screening
Products. This amendment is effective as between Chiron and Gen-Probe with
respect to Blood Screening Products only, and nothing herein shall affect any
rights or obligations of Gen-Probe or Bayer with respect to Clinical Diagnostic
Products.

        D.    The parties have discussed a revision to and clarification of
their respective rights and obligations with respect to Section 1.2.1, and have
agreed to make certain changes to the Agreement in connection therewith, in
accordance with the provisions of this Amendment No. 5.

Agreement

        NOW, THEREFORE, for and in consideration of the mutual covenants and
agreements set forth in this Amendment No. 5, the parties agree as follows:

        1.     Applicable Purchase Price. Section 1.2.1 of the Agreement shall
be and is hereby amended to read as follows:

        1.2.1 With respect to each Initial Blood Screening Assay, and each
Future Blood Screening Assay which includes as a constituent element an assay
for HCV (other than those sold pursuant to Sections 3.1.4(b) or 3.6), and except
as set forth in Section 1.2.2 below, an amount equal to Forty-five and
Seventy-five one hundredths percent (45.75%) of Net Sales thereof.

        2.     Major Distributor. All references in the Agreement to the Major
Distributor are hereby deleted. All licenses and rights granted, or to be
granted, by Gen-Probe to the Major Distributor are hereby terminated.

        3.     No Other Amendment. Except as is expressly set forth in this
Amendment No. 5, all other terms and conditions of the Agreement shall continue
in full force and effect.

        4.     Counterparts. This Amendment No. 5 may be executed in
counterparts, each of which shall be an original, and all of which together
shall constitute one and the same instrument.

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        IN WITNESS WHEREOF, the parties have caused this Amendment No. 5 to be
executed and the persons signing below warrant that they are duly authorized to
sign for and on behalf of the respective parties.

Gen-Probe:   Chiron:
GEN-PROBE INCORPORATED,
a Delaware corporation
 
CHIRON CORPORATION,
a Delaware corporation
By:
 
/s/  HANK NORDHOFF      

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By:
 
/s/  JACK GOLDSTEIN      

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Its: President & Chief Executive Officer
Date: November 10, 2003   Its: President, Chiron Blood Testing
Date: November 12, 2003

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Exhibit 10.327

AMENDMENT NO. 5 TO AGREEMENT
Recitals
Agreement