**SIXTH
      AMENDMENT TO 2005 CREDIT FACILITY**









THIS
      SIXTH AMENDMENT TO 2005 CREDIT FACILITY AGREEMENT (this " **Amendment** ")
      is
      made as of March 21, 2007, by and among Calypte Biomedical Corporation, a
      Delaware corporation (" **Issuer** "),
      and
      Marr Technologies, BV, a limited liability company established in the
      Netherlands (" **Purchaser** ").
      Unless otherwise defined herein, all capitalized terms used herein shall have
      the meanings given to them in the Credit Facility referred to
      below.




WHEREAS,
      Issuer and Purchaser are parties to the 2005 Credit Facility Agreement dated
      as
      of April 4, 2005, Amendment to 2005 Credit Facility dated as of November 30,
      2005, Second Amendment to 2005 Credit Facility dated as of February 22, 2006,
      Third Amendment to 2005 Credit Facility dated as of July 6, 2006, Fourth
      Amendment to 2005 Credit Facility dated as of December 22, 2006 and Fifth
      Amendment to 2005 Credit Facility dated as of February 6, 2007 (collectively,
      the " **Credit
      Facility** ");
      and




WHEREAS,
      the parties now desire to amend and modify the Credit Facility to provide for
      the extension of the maturity date for monies borrowed and certain other
      modifications and amendments agreed to by the parties.




NOW,
      THEREFORE, for good and valuable consideration, the receipt and sufficiency
      of
      which are hereby acknowledged, Issuer and Purchaser agree as
      follows:




1.  Section
      III.b. of the Credit Facility is hereby amended and restated to read in its
      entirety as follows:




"b .  Expiration
      of Agreement .
      This
      Agreement shall terminate on April 3, 2009.”




2.  Governing
      Law .
      This
      Amendment shall be governed by and construed under the laws of the State of
      Delaware, without regard to the conflicts of laws principles of the State of
      Delaware.




3.  Miscellaneous .
      Neither
      this Amendment nor any provision hereof may be changed, waived discharged or
      terminated orally, but only by an instrument in writing signed by the party
      against which enforcement of the change, waiver, discharge or termination is
      sought. This Amendment shall be binding upon Issuer and its successors and
      assigns, and all persons claiming under or through Issuer or any such successor
      or assign, and shall inure to the benefit of and be enforceable by Purchaser
      and
      its successors and assigns.




4.  Execution .
      This
      Amendment may be executed in two or more counterparts, all of which when taken
      together shall be considered one and the same agreement. In the event that
      any
      signature is delivered by facsimile transmission, such signature shall create
      a
      valid and binding obligation of the party executing with the same force and
      effect as if such facsimile signature page were an original
      thereof.




5.  Binding
      Effect .
      This
      Amendment shall not be binding upon the Company or the Issuer unless and until
      SF Capital Partners Ltd. (“ **SF** ”)
      has
      executed and delivered to the Company that certain Amendment to Secured 8%
      Convertible Promissory Notes in which SF agrees to change the maturity date
      to
      April 3, 2009 of all notes issued to it by the Company in connection with that
      certain Purchase Agreement dated April 4, 2005 (including, without limitation,
      any notes issued to it for the payment of interest).







6.  Effect
      of Amendment .
      Except
      for the amendment provided for herein, the Credit Facility shall remain
      unchanged and in full force and effect.




**IN
      WITNESS WHEREOF** ,
      each of
      the parties hereto has caused a counterpart of this Sixth Amendment to Credit
      Facility to be duly executed and delivered as of the date first above
      written.














CALYPTE
      BIOMEDICAL CORPORATION




By:





Its:





Date:
      ___________________________










MARR
      TECHNOLOGIES, BV




By:
 
 Its:
 
 Date:
        ___________________________