Exhibit 5.1


                               BARATTA & GOLDSTEIN
                                ATTORNEYS AT LAW
                                597 FIFTH AVENUE
                              NEW YORK, N.Y. 10017
                                   ----------
JOSEPH P. BARATTA                (212) 750-9700        FACSIMILE:(212) 7501-8297
HOWARD J. GOLDSTEIN                                         INFO@BARAGOLD.COM
    -----------
LOUIS R. AIDALA                                                 OF COUNSEL
JOAN PALERMO                                                MARGARET M. STANTON
JOSEPH A. BARATTA*                                            LINDA MARY ANOV
                                                            SAMUEL M. GREENFIELD
*  Admitted in NY and NJ

                                                December 23, 2004


Calypte Biomedical Corporation
5000 Hopyard Road, Suite 480
Pleasanton, CA  94588

                                       Re: Calypte Biomedical Corporation
                                           Registration Statement on Form SB-2
                                           File No.: 333-119646
                                           -----------------------------------

Ladies and Gentlemen:

We  have  acted  as  counsel  to  Calypte  Biomedical  Corporation,  a  Delaware
corporation (the "Company"), in connection with the Form SB-2 (the "Registration
Statement") filed with the Securities and Exchange Commission (the "Commission")
under the Securities Act of 1933, as amended (the "Act"),  for the  registration
under the Act of 1,172,205 shares of the Company's common stock, $0.03 par value
(the "Common Stock") as follows:

o     1,172,205 shares of common stock,  that have been previously issued to the
      selling  security  holder  in  connection  with a  License  Agreement  and
      Technology Transfer Agreement (the "License Agreement").

In  connection  with this  opinion,  we have  assumed  the  authenticity  of all
records, documents and instruments submitted to us as originals, the genuineness
of all  signatures,  the legal capacity of natural persons and the conformity to
the  originals  of all records,  documents  and  instruments  submitted to us as
copies.  We have based our  opinion  upon our review of the  following  records,
documents and instruments:

(a)   The Amended and Restated  Certificate of Incorporation of the Company,  as
      amended  to date,  certified  by the  Secretary  of State of the  State of
      Delaware as of December 17, 2004 and  certified to us by an officer of the
      Company as being  complete  and in full force and effect as of the date of
      this opinion.

(b)   The Bylaws of the  Company,  as  amended  to-date,  certified  to us by an
      officer of the Company as being  complete  and in full force and effect as
      of the date of this opinion.

(c)   A  Certificate  of Good  Standing  relating to the  Company  issued by the
      Secretary of State of the State of Delaware as of December 17, 2004.

(d)   A Certificate of an officer of the Company (i) attaching records certified
      to us as constituting  all records of proceedings and actions of the Board
      of Directors and  Stockholders of the Company  relating to the issuance of
      the Shares,  (ii) verifying  that the Amended and Restated  Certificate of
      Incorporation  of the Company is complete  and in full force and effect as
      of the date of this opinion,  and (iii)  certifying as to certain  factual
      matters including warranties and representations;





(e)   A Certificate of American  Stock Transfer and Trust Company,  the transfer
      agent of the  Company,  as to the number of shares of common  stock of the
      Company outstanding as of December 15, 2004;

(f)   The Registration Statement; and

(g)   The License Agreement (and schedules annexed thereto).

This opinion is limited to the Federal Law of the United States of America and
the General Corporation Law of the State of Delaware including statutory
provisions as well as applicable provisions of the Delaware Constitution and
reported judicial decisions interpreting these laws. We disclaim any opinion as
to any other statute, rule, regulation, ordinance, order or other promulgation
of any other jurisdiction or any regional or local governmental body.


Based upon the foregoing and our examination of such questions of law as we have
deemed necessary or appropriate for the purpose of this opinion and assuming
that all applicable federal and state securities laws are complied with, it is
our opinion that the Common Stock is duly authorized and validly issued, and
fully paid and nonassessable.


We  hereby  consent  to  the  filing  of  this  opinion  as an  Exhibit  to  the
Registration Statement and to the reference to us under the caption "Interest of
Named  Experts  and  Counsel"  in the  Registration  Statement.  In  giving  the
foregoing consent, we do not hereby admit that we are in the category of persons
whose  consent  is  required  under  Section  7 of  the  Act or  the  rules  and
regulations of the Commission.

                                                    Very truly yours,

                                                    BARATTA & GOLDSTEIN

                                                    /S/ BARATTA & GOLDSTEIN