UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION

                             Washington, D.C. 20549

                                    FORM 8-K

        Current Report Pursuant to Section 13 or 15(d) of the Securities
                              Exchange Act of 1934


         Date of Report (Date of earliest event reported) April 4, 2005


                         Calypte Biomedical Corporation
                         ------------------------------
               (Exact name of Company as specified in its charter)
<TABLE>
<CAPTION>

<S>                            <C>                          <C>
Delaware                              000-20985                          06-1226727
--------                              ---------                          ----------
(State or Other Jurisdiction)  (Commission File Number)      (I.R.S. Employer Identification)
of Incorporation)

</TABLE>

                5000 Hopyard Rd., Suite 480, Pleasanton CA 94588
                ------------------------------------------------

               (Address of principal executive offices) (Zip Code)

       Registrant's telephone number, including area code: (925) 730-7200


                                       N/A
                                       ---

          (Former name or former address, if changed since last report)

[_]   Written  communication  pursuant to Rule 425 under the  Securities Act (17
      CFR 230.425)

[_]   Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR
      240.14a-12)

[_]   Pre-commencement  communications  pursuant  to  Rule  14d-2(b)  under  the
      Exchange Act (17 CFR 240.14d-2(b))

[_]   Pre-commencement  communications  pursuant  to  Rule  13e-4(c)  under  the
      Exchange Act (17 CFR 40.13e-4(c))


<PAGE>


ITEM 2.03 CREATION OF A DIRECT  FINANCIAL  OBLIGATION OR AN OBLIGATION  UNDER AN
OFF-BALANCE SHEET ARRANGEMENT OF A REGISTRANT.

(a) On April 4, 2005,  the  Registrant  (the  "Company")  issued $8.0 million of
Secured 8% Senior  Convertible Notes (the "Notes") and warrants (the "Warrants")
to purchase shares (the "Warrant  Shares") of its common stock,  $0.03 par value
(the  "Common  Stock") in a private  placement  pursuant to Section  4(2) of the
Securities  Act of 1933,  as amended and Rule 506  thereunder.  The Company used
$2,000,000  from the proceeds of the placement to repay the 7%  Promissory  Note
issued to Marr  Technologies  BV ("Marr") in January  2005 and which it extended
through April 30, 2005. The Company intends to use the remainder of the proceeds
for general working capital purposes as well as for the commercialization of its
rapid tests for HIV-1/2 diagnosis.

      Under the terms of the  purchase  agreements  between  the Company and the
investors  (the  "Purchase  Agreement(s)"),  the  Company  issued to  accredited
investors $8.0 million of Secured 8% Senior  Convertible  Notes having a term of
two years and convertible into approximately 26.7 million shares of Common Stock
at $0.30 per share,  five (5) year Series A warrants  to purchase  approximately
26.7 million  Warrant  Shares,  with each Series A warrant  exercisable  after a
period of six months and  having an  exercise  price of $0.325 and five (5) year
Series B warrants to purchase  approximately  12.0 million Warrant Shares,  with
each  Series B warrant  exercisable  after a period of six  months and having an
exercise  price of $0.325.  After a period of 18 months and if the daily  volume
weighted  average  price of the Common Stock is greater than $0.60 per share for
20 consecutive trading days, and subject to certain trading volume restrictions,
the Company has the right to force the conversion of any unconverted  Notes into
shares of Common Stock.  In the event of a change of control while the Notes are
outstanding,  the investors  have the right to put the Notes back to the Company
at 115% of the face amount of the Notes, plus accrued interest. The Company also
entered into a Security  Agreement granting to the investors a security interest
in and lien on all of it assets,  subject to a security  interest  of up to $1.0
million that was  previously  granted under the terms of an equipment  financing
arrangement.  After a period  of six  months  and if the daily  volume  weighted
average price of the Common Stock is greater than approximately $0.542 per share
for  20  consecutive  trading  days,  and  subject  to  certain  trading  volume
restrictions,  the Company  has the right to force the  exercise of the Series B
Warrants.

      The Company  entered into  registration  rights  agreements with investors
(the  "Registration  Rights  Agreement")  requiring  it to  file a  registration
statement for the re-sale of the Common Stock  underlying  the Notes and Warrant
Shares  within  45  days  of  closing  and  to  achieve   effectiveness  of  the
registration  statement  within 120 days of  closing.  In the event the  Company
fails to register the Common Stock within the prescribed  time, the Company will
be obligated to pay the investors 1% of the  aggregate  face amount of the Notes
as partial  liquidated  damages.  The Company  will be required to pay 2% of the
aggregate face amount of the Notes as additional  partial  liquidated damages on
each monthly  anniversary  (or pro-rata  amount thereof) of the date the Company
was  required  to have the  shares of Common  Stock  registered.  Under  certain
circumstances prior to the effectiveness of the registration statement, both the
Series A and Series B Warrants have a cashless exercise feature.

      Under  certain  circumstances  and subject to  approval  by the  Company's
stockholders,  the Purchase Agreement provides for adjustments in the conversion
price of the Notes and the  exercise  price of the Series A Warrant in the event
the  Company  issues  shares of Common  Stock or common  stock  equivalents,  as
defined in the Purchase  Agreement,  within one year of the first anniversary of
the closing  date at a price less than $0.30 per share with respect to the Notes
and at a price less than $0.325 per share with respect to the Series A Warrants.
This provision  terminates upon the earlier of one year or upon conversion of an
investor's Note or exercise of its Series A Warrant.

      The Company also  granted the  investors a right of  participation  in any
future offerings the Company undertakes within one (1) year of the closing date.

      Marr, the Company's largest stockholder,  participated in the placement by
purchasing  units which  consisted of a $2.8 million Note, a Series A Warrant to
purchase  approximately  9.3  million  Warrant  Shares and a Series B Warrant to
purchase approximately 4.2 million Warrant Shares.

<PAGE>

      In  connection  with the  placement,  the Company paid finders fees and/or
placement  agent  fees  to  non-exclusive  finders  of up to 7% of  the  related
investment amount in cash and issued Notes and warrants to purchase Common Stock
in amounts of up to 4% of the related Common Stock issued.

      The  Company  incorporates  the terms of the  Purchase  Agreement,  Notes,
Series A Warrant,  Series B Warrant,  Registration Rights Agreement and Security
Agreement which are annexed hereto and made a part of this current report.

      On April 4, 2005,  the  Company  and the  investors  which are  parties to
securities  purchase agreements and warrants dated as of May 28, 2004 or July 9,
2004 (the  "2004  PIPEs")  agreed to amend  those  agreements  with  respect  to
anti-dilution  rights  granted  in the  purchase  agreement  and  warrants.  The
securities   purchase  agreements  and  warrants  for  the  2004  PIPEs  contain
anti-dilution  provisions that require the Company to issue additional shares of
common stock, reprice the existing warrants and issue additional warrants to the
investors if it raises  additional  equity  financing at a price below $0.40 per
share in the year  following  the  closing of the  repective  transactions  (the
"Anti-Dilution Entitlements").  The issuance of the Notes and Warrants described
above triggers the Anti-Dilution Entitlements.

      The Company and the  investors  in the 2004 PIPEs have agreed to amend the
provisions  of the  respective  purchase  agreements  and  warrants  so that the
Anti-Dilution  Entitlements  do not arise  unless and until they are approved by
the Company's stockholders at the next annual meeting of stockholders, which the
Company  expects to hold in June 2005. In  consideration  of the amendment,  and
subject  to  stockholder  approval,  the  Company  has  agreed  to issue to each
investor in the 2004 PIPEs  additional  shares of Common  Stock and a warrant to
purchase  additional  shares of Common  Stock (the  "Additional  Shares") for no
additional  consideration  from the  investors.  Additionally,  the  Company has
agreed to  reduce  the  exercise  price of all the  warrants  issued in the 2004
PIPE's.  Assuming its stockholders approve the Anti-Dilution  Entitlements,  the
Company  expects to (a) issue  approximately  7.1 million  additional  shares of
Common Stock for no additional  consideration from the investors, (b) reduce the
exercise price of the investors' existing warrants from $0.50 per share to $0.45
per  share;  and (c)  issue  warrants  to  purchase  approximately  1.3  million
additional  shares of our Common Stock at an exercise price of $0.325 per share.
Certain  of the  investors  in the 2004  PIPEs  who held  shares  prior to their
investment in those transactions and who also continue to be stockholders of the
Company have entered into a voting  agreement to vote their  eligible  shares in
favor of  approving  the  Anti-Dilution  Entitlements  at the annual  meeting of
stockholders.

      The Company incorporates the terms of the Amendment to Securities Purchase
Agreement which is annexed hereto and made a part of this current report.

      Additionally,  on April 4, 2005 the Company entered into an agreement with
Marr under which Marr agreed to purchase up to $5,500,000 of 9% Promissory Notes
that the  Company may issue  between  April 5, 2005 and  December  31, 2005 (the
"Credit  Facility").  Any notes  issued  under the Credit  Facility  will be due
twelve months after  issuance,  but in no event later than May 31, 2006 and will
require  the  unanimous  approval of the  Company's  Board of  Directors,  which
includes  two  members  originally  nominated  by Marr  pursuant  to a  previous
investment agreement.. The $5.5 million commitment amount will be reduced dollar
for dollar by the  amount of any  subsequent  equity  financing,  including  any
proceeds from the forced  exercise of the Series B Warrants,  the Company raises
after  April 4,  2005.  Proceeds  from the  issuance  of notes  under the Credit
Facility, if any, may be used for general corporate purposes.

      In  consideration  of the Credit  Facility,  the  Company  granted  Marr a
five-year warrant, exercisable after a period of six months, to purchase 500,000
shares of the  Company's  common  stock at an exercise  price of $0.40 per share
with piggyback  registration  rights for the underlying  shares of common stock.
The  Company  intends  to  register  for  re-sale  the  shares of  Common  Stock
underlying this warrant with the shares to be registered in conjunction with the
shares  underlying  the  Notes  and  Series A  Warrants  and  Series B  Warrants
described above.

      The  Company  hereby  incorporates  by  reference  the terms of the Credit
Facility  Agreement  which is  annexed  hereto  and made a part of this  current
report.

      Also included  herein is the Company's  press release issued April 5, 2005
which announced the issuance of the Notes and Warrants.


<PAGE>


ITEM 9.01. FINANCIAL STATEMENTS AND EXHIBITS

         (c)      Exhibits

                  Exhibit No.                   Description
                  -----------                   -----------

                  10.156        Form of Purchase Agreement dated April 4, 2005.


                  10.157        Form of Secured 8% Convertible Promissory Note
                                dated April 4, 2005.


                  10.158        Form of Registration Rights Agreement dated
                                April 4, 2005.


                  10.159        Form of Series A Warrant dated April 4, 2005.


                  10.160        Form of Series B Warrant dated April 4, 2005.


                  10.161        Form of Security Agreement dated April 4, 2005.


                  10.162        Form of Amendment to Securities Purchase
                                Agreement effective as of April 4, 2005.


                  10.163        2005 Marr Credit Facility Agreement dated April
                                4, 2005.

                  99.1          Press release dated April 5, 2005.



                                   SIGNATURES

Pursuant  to the  requirement  of the  Securities  Exchange  Act  of  1934,  the
Registrant  has duly  caused  this  report  to be  signed  on its  behalf by the
undersigned hereunto duly authorized.

Date:  Pleasanton, California
       April 5, 2005


                        Calypte Biomedical Corporation

                        By: /s/  Richard D. Brounstein
                            -------------------------------------------
                           Richard D. Brounstein
                           Executive Vice President and Chief Financial Officer
{"company-data": {"conformed-name": "CALYPTE BIOMEDICAL CORP", "cik": "0000899426", "assigned-sic": "3826", "irs-number": "061226727", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "8-K", "act": "34", "file-number": "001-32280", "film-number": "05733581"}, "business-address": {"street1": "5000 HOPYARD ROAD, SUITE 480", "city": "PLEASANTON", "state": "CA", "zip": "94588", "phone": "9257307200"}, "mail-address": {"street1": "5000 HOPYARD ROAD, SUITE 480", "city": "PLEASANTON", "state": "CA", "zip": "94588"}}
UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION

                             Washington, D.C. 20549

                                    FORM 8-K

        Current Report Pursuant to Section 13 or 15(d) of the Securities
                              Exchange Act of 1934

         Date of Report (Date of earliest event reported) April 4, 2005

                         Calypte Biomedical Corporation
                         ------------------------------
               (Exact name of Company as specified in its charter)
Delaware                              000-20985                          06-1226727
--------                              ---------                          ----------
(State or Other Jurisdiction)  (Commission File Number)      (I.R.S. Employer Identification)
of Incorporation)
5000 Hopyard Rd., Suite 480, Pleasanton CA 94588
                ------------------------------------------------

               (Address of principal executive offices) (Zip Code)

       Registrant's telephone number, including area code: (925) 730-7200

                                       N/A
                                       ---

          (Former name or former address, if changed since last report)

[_]   Written  communication  pursuant to Rule 425 under the  Securities Act (17
      CFR 230.425)

[_]   Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR
      240.14a-12)

[_]   Pre-commencement  communications  pursuant  to  Rule  14d-2(b)  under  the
      Exchange Act (17 CFR 240.14d-2(b))

[_]   Pre-commencement  communications  pursuant  to  Rule  13e-4(c)  under  the
      Exchange Act (17 CFR 40.13e-4(c))
ITEM 2.03 CREATION OF A DIRECT  FINANCIAL  OBLIGATION OR AN OBLIGATION  UNDER AN
OFF-BALANCE SHEET ARRANGEMENT OF A REGISTRANT.

(a) On April 4, 2005,  the  Registrant  (the  "Company")  issued $8.0 million of
Secured 8% Senior  Convertible Notes (the "Notes") and warrants (the "Warrants")
to purchase shares (the "Warrant  Shares") of its common stock,  $0.03 par value
(the  "Common  Stock") in a private  placement  pursuant to Section  4(2) of the
Securities  Act of 1933,  as amended and Rule 506  thereunder.  The Company used
$2,000,000  from the proceeds of the placement to repay the 7%  Promissory  Note
issued to Marr  Technologies  BV ("Marr") in January  2005 and which it extended
through April 30, 2005. The Company intends to use the remainder of the proceeds
for general working capital purposes as well as for the commercialization of its
rapid tests for HIV-1/2 diagnosis.

      Under the terms of the  purchase  agreements  between  the Company and the
investors  (the  "Purchase  Agreement(s)"),  the  Company  issued to  accredited
investors $8.0 million of Secured 8% Senior  Convertible  Notes having a term of
two years and convertible into approximately 26.7 million shares of Common Stock
at $0.30 per share,  five (5) year Series A warrants  to purchase  approximately
26.7 million  Warrant  Shares,  with each Series A warrant  exercisable  after a
period of six months and  having an  exercise  price of $0.325 and five (5) year
Series B warrants to purchase  approximately  12.0 million Warrant Shares,  with
each  Series B warrant  exercisable  after a period of six  months and having an
exercise  price of $0.325.  After a period of 18 months and if the daily  volume
weighted  average  price of the Common Stock is greater than $0.60 per share for
20 consecutive trading days, and subject to certain trading volume restrictions,
the Company has the right to force the conversion of any unconverted  Notes into
shares of Common Stock.  In the event of a change of control while the Notes are
outstanding,  the investors  have the right to put the Notes back to the Company
at 115% of the face amount of the Notes, plus accrued interest. The Company also
entered into a Security  Agreement granting to the investors a security interest
in and lien on all of it assets,  subject to a security  interest  of up to $1.0
million that was  previously  granted under the terms of an equipment  financing
arrangement.  After a period  of six  months  and if the daily  volume  weighted
average price of the Common Stock is greater than approximately $0.542 per share
for  20  consecutive  trading  days,  and  subject  to  certain  trading  volume
restrictions,  the Company  has the right to force the  exercise of the Series B
Warrants.

      The Company  entered into  registration  rights  agreements with investors
(the  "Registration  Rights  Agreement")  requiring  it to  file a  registration
statement for the re-sale of the Common Stock  underlying  the Notes and Warrant
Shares  within  45  days  of  closing  and  to  achieve   effectiveness  of  the
registration  statement  within 120 days of  closing.  In the event the  Company
fails to register the Common Stock within the prescribed  time, the Company will
be obligated to pay the investors 1% of the  aggregate  face amount of the Notes
as partial  liquidated  damages.  The Company  will be required to pay 2% of the
aggregate face amount of the Notes as additional  partial  liquidated damages on
each monthly  anniversary  (or pro-rata  amount thereof) of the date the Company
was  required  to have the  shares of Common  Stock  registered.  Under  certain
circumstances prior to the effectiveness of the registration statement, both the
Series A and Series B Warrants have a cashless exercise feature.

      Under  certain  circumstances  and subject to  approval  by the  Company's
stockholders,  the Purchase Agreement provides for adjustments in the conversion
price of the Notes and the  exercise  price of the Series A Warrant in the event
the  Company  issues  shares of Common  Stock or common  stock  equivalents,  as
defined in the Purchase  Agreement,  within one year of the first anniversary of
the closing  date at a price less than $0.30 per share with respect to the Notes
and at a price less than $0.325 per share with respect to the Series A Warrants.
This provision  terminates upon the earlier of one year or upon conversion of an
investor's Note or exercise of its Series A Warrant.

      The Company also  granted the  investors a right of  participation  in any
future offerings the Company undertakes within one (1) year of the closing date.

      Marr, the Company's largest stockholder,  participated in the placement by
purchasing  units which  consisted of a $2.8 million Note, a Series A Warrant to
purchase  approximately  9.3  million  Warrant  Shares and a Series B Warrant to
purchase approximately 4.2 million Warrant Shares.
In  connection  with the  placement,  the Company paid finders fees and/or
placement  agent  fees  to  non-exclusive  finders  of up to 7% of  the  related
investment amount in cash and issued Notes and warrants to purchase Common Stock
in amounts of up to 4% of the related Common Stock issued.

      The  Company  incorporates  the terms of the  Purchase  Agreement,  Notes,
Series A Warrant,  Series B Warrant,  Registration Rights Agreement and Security
Agreement which are annexed hereto and made a part of this current report.

      On April 4, 2005,  the  Company  and the  investors  which are  parties to
securities  purchase agreements and warrants dated as of May 28, 2004 or July 9,
2004 (the  "2004  PIPEs")  agreed to amend  those  agreements  with  respect  to
anti-dilution  rights  granted  in the  purchase  agreement  and  warrants.  The
securities   purchase  agreements  and  warrants  for  the  2004  PIPEs  contain
anti-dilution  provisions that require the Company to issue additional shares of
common stock, reprice the existing warrants and issue additional warrants to the
investors if it raises  additional  equity  financing at a price below $0.40 per
share in the year  following  the  closing of the  repective  transactions  (the
"Anti-Dilution Entitlements").  The issuance of the Notes and Warrants described
above triggers the Anti-Dilution Entitlements.

      The Company and the  investors  in the 2004 PIPEs have agreed to amend the
provisions  of the  respective  purchase  agreements  and  warrants  so that the
Anti-Dilution  Entitlements  do not arise  unless and until they are approved by
the Company's stockholders at the next annual meeting of stockholders, which the
Company  expects to hold in June 2005. In  consideration  of the amendment,  and
subject  to  stockholder  approval,  the  Company  has  agreed  to issue to each
investor in the 2004 PIPEs  additional  shares of Common  Stock and a warrant to
purchase  additional  shares of Common  Stock (the  "Additional  Shares") for no
additional  consideration  from the  investors.  Additionally,  the  Company has
agreed to  reduce  the  exercise  price of all the  warrants  issued in the 2004
PIPE's.  Assuming its stockholders approve the Anti-Dilution  Entitlements,  the
Company  expects to (a) issue  approximately  7.1 million  additional  shares of
Common Stock for no additional  consideration from the investors, (b) reduce the
exercise price of the investors' existing warrants from $0.50 per share to $0.45
per  share;  and (c)  issue  warrants  to  purchase  approximately  1.3  million
additional  shares of our Common Stock at an exercise price of $0.325 per share.
Certain  of the  investors  in the 2004  PIPEs  who held  shares  prior to their
investment in those transactions and who also continue to be stockholders of the
Company have entered into a voting  agreement to vote their  eligible  shares in
favor of  approving  the  Anti-Dilution  Entitlements  at the annual  meeting of
stockholders.

      The Company incorporates the terms of the Amendment to Securities Purchase
Agreement which is annexed hereto and made a part of this current report.

      Additionally,  on April 4, 2005 the Company entered into an agreement with
Marr under which Marr agreed to purchase up to $5,500,000 of 9% Promissory Notes
that the  Company may issue  between  April 5, 2005 and  December  31, 2005 (the
"Credit  Facility").  Any notes  issued  under the Credit  Facility  will be due
twelve months after  issuance,  but in no event later than May 31, 2006 and will
require  the  unanimous  approval of the  Company's  Board of  Directors,  which
includes  two  members  originally  nominated  by Marr  pursuant  to a  previous
investment agreement.. The $5.5 million commitment amount will be reduced dollar
for dollar by the  amount of any  subsequent  equity  financing,  including  any
proceeds from the forced  exercise of the Series B Warrants,  the Company raises
after  April 4,  2005.  Proceeds  from the  issuance  of notes  under the Credit
Facility, if any, may be used for general corporate purposes.

      In  consideration  of the Credit  Facility,  the  Company  granted  Marr a
five-year warrant, exercisable after a period of six months, to purchase 500,000
shares of the  Company's  common  stock at an exercise  price of $0.40 per share
with piggyback  registration  rights for the underlying  shares of common stock.
The  Company  intends  to  register  for  re-sale  the  shares of  Common  Stock
underlying this warrant with the shares to be registered in conjunction with the
shares  underlying  the  Notes  and  Series A  Warrants  and  Series B  Warrants
described above.

      The  Company  hereby  incorporates  by  reference  the terms of the Credit
Facility  Agreement  which is  annexed  hereto  and made a part of this  current
report.

      Also included  herein is the Company's  press release issued April 5, 2005
which announced the issuance of the Notes and Warrants.
ITEM 9.01. FINANCIAL STATEMENTS AND EXHIBITS

         (c)      Exhibits

                  Exhibit No.                   Description
                  -----------                   -----------

                  10.156        Form of Purchase Agreement dated April 4, 2005.

                  10.157        Form of Secured 8% Convertible Promissory Note
                                dated April 4, 2005.

                  10.158        Form of Registration Rights Agreement dated
                                April 4, 2005.

                  10.159        Form of Series A Warrant dated April 4, 2005.

                  10.160        Form of Series B Warrant dated April 4, 2005.

                  10.161        Form of Security Agreement dated April 4, 2005.

                  10.162        Form of Amendment to Securities Purchase
                                Agreement effective as of April 4, 2005.

                  10.163        2005 Marr Credit Facility Agreement dated April
                                4, 2005.

                  99.1          Press release dated April 5, 2005.

                                   SIGNATURES

Pursuant  to the  requirement  of the  Securities  Exchange  Act  of  1934,  the
Registrant  has duly  caused  this  report  to be  signed  on its  behalf by the
undersigned hereunto duly authorized.

Date:  Pleasanton, California
       April 5, 2005

                        Calypte Biomedical Corporation

                        By: /s/  Richard D. Brounstein
                            -------------------------------------------
                           Richard D. Brounstein
                           Executive Vice President and Chief Financial Officer