Exhibit 5.1

                               BARATTA & GOLDSTEIN
                                ATTORNEYS AT LAW
                                597 FIFTH AVENUE
                              NEW YORK, N.Y. 10017

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JOSEPH P. BARATTA                (212) 750-9700       FACSIMILE:  (212) 750-8297
HOWARD J. GOLDSTEIN                                        INFO@BARAGOLD.COM
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LOUIS R. AIDALA                                               OF COUNSEL
JOAN PALERMO                                              MARGARET M. STANTON
JOSEPH A. BARATTA*                                          LINDA MARYANOV
                                                         SAMUEL M. GREENFIELD
*Admitted in NY and NJ

                                                 July 2, 2004


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

                                        Re: Registration Statement on Form SB-2


Ladies and Gentlemen:

We have acted as counsel to Calypte Biomedical Corporation, a Delaware
corporation (the "Company"), in connection with the issuance and sale by the
Company of up to 83,056,050 shares of the Company's common stock, $0.03 par
value (the "Common Stock") as follows:

    o   3,088,554 shares of Common Stock that have previously been issued to
        certain selling security holders as a result of o their conversions of
        $3,232,000 aggregate original principal amount of the Company's 8%
        secured convertible notes, plus interest and liquidated damages;

    o   4,725,414 shares of Common Stock, including 563,538 Shares that may be
        issued upon the conversion of the remaining $91,597 aggregate principal
        amount of the Company's 10% convertible debentures, including accrued
        interest, extension fees and other amounts, and 4,161,876 shares of
        Common Stock that have been previously issued to a selling security
        holder upon the conversion of $1,100,072 principal amount of the
        Company's 10% convertible debentures, plus accrued interest and
        liquidated damages;

    o   10,351,061 shares of Common Stock, including 682,646 shares that may be
        issued upon the conversion of the $66,113 aggregate principal amount of
        the Company's 12% convertible debentures including accrued interest and
        other amounts, 100,000 shares of Common Stock underlying warrants issued
        as part of the consideration for a 12% convertible debenture
        transaction, and 9,568,415 shares of Common Stock previously issued to
        certain selling security holders upon their conversions of $1,933,887
        aggregate principal amount of the Company's 12% convertible debentures,
        plus accrued interest and liquidated damages;

    o   28,333,333 shares of Common Stock that have previously been issued to a
        selling security holder in connection with a $2,500,000 PIPE transaction
        at $0.30 per share and a $10,000,000 PIPE transaction at $0.50 per
        share;

    o   3,265,188 shares of Common Stock, including 2,569,727 shares that have
        previously been issued to certain selling security holders in connection
        with agreements in which the Company obtained goods and services in
        return for the issuance of shares of Common Stock, and 695,461 shares of
        Common Stock underlying warrants or other agreements between the Company
        and certain selling security holders in connection with which the
        Company has obtained goods and services;

    o   1,275,000 shares of Common Stock underlying warrants issued in
        connection with a $10,000,000 5% Promissory Note Commitment Agreement
        and subsequent amendments thereof; and



    o   32,017,500 shares of Common Stock, including 23,250,000 shares that have
        been previously issued to selling security holders in connection with a
        $9,300,000 May 2004 PIPE transaction at $0.40 per share and an
        additional 8,767,500 shares underlying warrants to purchase Common Stock
        at $0.50 per share issued in conjunction therewith.

Capitalized terms used without definition in this opinion have the meanings
given to them in the respective agreements (including the schedules thereto).

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 June 24, 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 June 24, 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;

(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 July 2, 2004;

(f)  The Registration Statement;

(g)  The respective agreements;

(h)  The form of the debentures; and

(i)  The form of notes.

This opinion is limited to the Federal Law of the United States of America and
the General Corporation Law of the State of Delaware which we have for purposes
of this opinion assumed are the same as the laws of the State of New York. 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.

Our opinion expressed herein assumes that the full consideration stated in the
Agreements and set by the Board of Directors when authorizing the issuance of
the Shares.

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 (i) the Registration Statement becomes and remains effective during the



period when the Shares are offered and sold; (ii) the Shares are issued in
accordance with the terms of the Agreements and the resolutions authorizing
their issuance; (iii) appropriate stock certificates evidencing the Shares are
executed and delivered; and (iv) all applicable securities laws are complied
with, it is our opinion that when issued, the Shares will be duly authorized and
validly issued, and fully paid and nonassessable.

This opinion is rendered to you in connection with the Registration Statement
and is solely for your benefit. This opinion may not be relied upon by you for
any other purpose, or relied upon by any other person, firm, corporation or
other entity for any purpose, without our prior written consent. We disclaim any
obligation to advise you of any change of law that occurs, or any facts of which
we may become aware, after the date of this opinion.

We hereby consent to the filing of this opinion as an Exhibit to the
Registration Statement.

                                                     Very truly yours,

                                                     BARATTA & GOLDSTEIN

                                                     /s/ Baratta & Goldstein