EXHIBIT D

NEITHER  THESE  SECURITIES  NOR THE  SECURITIES  ISSUABLE UPON EXERCISE OF THESE
SECURITIES HAVE BEEN  REGISTERED WITH THE SECURITIES AND EXCHANGE  COMMISSION OR
THE  SECURITIES  COMMISSION  OF ANY STATE IN  RELIANCE  UPON AN  EXEMPTION  FROM
REGISTRATION  UNDER THE  SECURITIES  ACT OF 1933,  AS AMENDED  (THE  "SECURITIES
ACT"),  AND,  ACCORDINGLY,  MAY NOT BE OFFERED  OR SOLD  EXCEPT  PURSUANT  TO AN
EFFECTIVE  REGISTRATION  STATEMENT  UNDER THE  SECURITIES  ACT OR PURSUANT TO AN
AVAILABLE  EXEMPTION FROM, OR IN A TRANSACTION NOT SUBJECT TO, THE  REGISTRATION
REQUIREMENTS  OF THE  SECURITIES  ACT AND IN ACCORDANCE  WITH  APPLICABLE  STATE
SECURITIES  LAWS AS EVIDENCED BY A LEGAL OPINION OF COUNSEL TO THE TRANSFEROR TO
SUCH  EFFECT,  THE  SUBSTANCE  OF WHICH SHALL BE  REASONABLY  ACCEPTABLE  TO THE
COMPANY.  THESE  SECURITIES AND THE  SECURITIES  ISSUABLE UPON EXERCISE OF THESE
SECURITIES MAY BE PLEDGED IN CONNECTION  WITH A BONA FIDE MARGIN ACCOUNT SECURED
BY SUCH SECURITIES.

                         CALYPTE BIOMEDICAL CORPORATION

                                SERIES B WARRANT

Warrant No. [  ]                             Original Issue Date:  April 4, 2005

      CALYPTE BIOMEDICAL  CORPORATION,  a Delaware  corporation (the "COMPANY"),
hereby  certifies that, for value received,  [ ] or its registered  assigns (the
"HOLDER"),  is  entitled  to  purchase  from  the  Company up to a total of [ ]1
shares of Common Stock (each such share, a "WARRANT  SHARE" and all such shares,
the "WARRANT SHARES"),  at any time and from time to time from and after the six
month  anniversary of the Original Issue Date and through and including April 3,
2010 (the "EXPIRATION DATE"), and subject to the following terms and conditions:

      1.  Definitions.  As used in this Warrant,  the following terms shall have
the respective  definitions set forth in this Section 1. Capitalized  terms that
are used and not  defined  in this  Warrant  that are  defined  in the  Purchase
Agreement (as defined below) shall have the respective  definitions set forth in
the Purchase Agreement.

      "BUSINESS DAY" means any day except Saturday, Sunday and any day that is a
federal  legal  holiday  in  the  United  States  or  a  day  on  which  banking
institutions in the State of New York are authorized or required by law or other
government action to close.


--------------------
1  A  number of shares equal to 45% of the number of shares into which the Notes
may be converted.

<PAGE>

      "COMMON  STOCK" means the common stock of the Company,  par value $.03 per
share,  and any  securities  into  which  such  common  stock may  hereafter  be
reclassified.

      "EXERCISE PRICE" means the greater of (i) $0.325, subject to adjustment in
accordance  with Section 9, and (ii) the last trade price of the Common Stock on
the Closing Date or the date of the Purchase Agreement (whichever is greater).

      "FUNDAMENTAL  TRANSACTION"  means any of the  following:  (1) the  Company
effects any merger or  consolidation of the Company with or into another Person,
(2) the Company  effects any sale of all or  substantially  all of its assets in
one or a series of related transactions,  (3) any tender offer or exchange offer
(whether  by the  Company or  another  Person) is  completed  pursuant  to which
holders of Common  Stock are  permitted  to tender or exchange  their shares for
other   securities,   cash  or  property,   or  (4)  the  Company   effects  any
reclassification  of the Common Stock or any compulsory share exchange  pursuant
to which the Common Stock is  effectively  converted into or exchanged for other
securities, cash or property.

      "ORIGINAL ISSUE DATE" means the Original Issue Date first set forth on the
first page of this Warrant.

      "NEW YORK COURTS" means the state and federal  courts  sitting in the City
of New York, Borough of Manhattan.

      "PURCHASE AGREEMENT" means the Purchase  Agreement,  dated  April 4, 2005,
to which the Company and the original Holder are parties.

      "TRADING  DAY"  means (i) a day on which the  Common  Stock is traded on a
Trading Market (other than the OTC Bulletin Board),  or (ii) if the Common Stock
is not listed on a Trading Market (other than the OTC Bulletin  Board), a day on
which the Common Stock is traded in the over-the-counter  market, as reported by
the OTC  Bulletin  Board,  or (iii) if the  Common  Stock is not  quoted  on any
Trading   Market,   a  day  on  which  the   Common   Stock  is  quoted  in  the
over-the-counter   market  as  reported  by  the   National   Quotation   Bureau
Incorporated (or any similar  organization or agency succeeding to its functions
of reporting prices);  provided,  that in the event that the Common Stock is not
listed or quoted as set forth in (i),  (ii) and (iii)  hereof,  then Trading Day
shall mean a Business Day.

      "WARRANT  EQUITY  CONDITIONS  ARE  SATISFIED"  means,  as of any  date  of
determination,  that each of the following conditions is (or would be) satisfied
on such  date,  if the  Company  were to issue on such  date all of the  Warrant
Shares then issuable  upon exercise in full of all the Warrants:  (i) the number
of authorized  but unissued and otherwise  unreserved  shares of Common Stock is
sufficient for such issuance,  (ii) the Common Stock is listed or quoted (and is
not  suspended  from  trading) on an  Eligible  Market and such shares of Common
Stock are approved for listing on such Eligible Market upon issuance, (iii) such
Common Stock is registered for resale under the  Registration  Statement and the
prospectus  under such  Registration  Statement is available for the sale of all
Registrable Securities held by the Holder, (iv) such issuance would be permitted
in full without violating Section 11 or the rules or regulations of the Eligible
Market on which such shares are listed or quoted,  (v) both  immediately  before
and after  giving  effect  thereto,  no Default  under the Notes  shall or would
exist,  and (vi) no public  announcement  of a  pending  or  proposed  Change of
Control transaction has occurred that has not been consummated.

                                       2
<PAGE>

      2.  Registration of Warrant.  The Company shall register this Warrant upon
records  to be  maintained  by  the  Company  for  that  purpose  (the  "WARRANT
REGISTER"),  in the name of the  record  Holder  hereof  from time to time.  The
Company may deem and treat the registered Holder of this Warrant as the absolute
owner hereof for the purpose of any exercise  hereof or any  distribution to the
Holder, and for all other purposes, absent actual notice to the contrary.

      3.  Registration of Transfers.  The Company shall register the transfer of
any portion of this  Warrant in the Warrant  Register,  upon  surrender  of this
Warrant,  with the Form of Assignment attached hereto duly completed and signed,
to the Company at its address  specified  herein.  Upon any such registration or
transfer,  a new Warrant to purchase Common Stock, in substantially  the form of
this Warrant (any such new Warrant, a "NEW Warrant"),  evidencing the portion of
this Warrant so transferred  shall be issued to the transferee and a New Warrant
evidencing  the remaining  portion of this Warrant not so  transferred,  if any,
shall be issued to the transferring Holder. The acceptance of the New Warrant by
the transferee  thereof shall be deemed the acceptance by such transferee of all
of the rights and obligations of a holder of a Warrant.

      4. Exercise and Duration of Warrants.

            (a) This Warrant shall be exercisable  by the  registered  Holder at
any time and from time to time from and after the six month  anniversary  of the
Original Issue Date and through and including the Expiration Date. At 6:30 p.m.,
California  time  on the  Expiration  Date,  the  portion  of this  Warrant  not
exercised prior thereto shall be and become void and of no value.  Except as set
forth in subsection  (b) hereof,  the Company may not call or redeem any portion
of this Warrant without the prior written consent of the affected Holder.

            (b) Subject to the  provisions  of this  Section  4(b),  at any time
after this  Warrant may be  exercised,  the Company may deliver  (via  certified
United  States mail with a return  receipt  requested)  a written  notice  (such
notice,  a "COMPANY  EXERCISE  NOTICE") to the Holder within five days after any
day (such day, the "Test Date") on which the  conditions  in (i), (ii) and (iii)
below shall be satisfied, requiring the Holder to exercise at the Exercise Price
all (but not less than all) of this  Warrant,  provided  that:  (i) the VWAP for
each of 20 consecutive Trading Days prior to the Test Date is greater  than  the
price per share derived by  multiplying  the Exercise  Price by the number 1.667
(subject to equitable  adjustment as a result of the events set forth in Section
9), on each date during the entire  period  referred to in this clause (i), (ii)
the Warrant Equity Conditions Are Satisfied, and (iii) the average daily trading
volume of the Common Stock during the entire  period  referred to in this clause
(i) shall be at least  450,000  shares  (subject to  equitable  adjustment  as a
result of  intervening  stock splits and reverse stock  splits).  Subject to the
terms and  conditions of this Section 4(b), the Company shall exercise its right
to cause the exercise of this Warrant  pursuant to a Company  Exercise Notice on
the 10th Trading Day  immediately  succeeding  the date of the Company  Exercise
Notice (the "COMPANY EXERCISE DATE").  Notwithstanding  anything to the contrary
set forth in this  Warrant,  the Holder  shall  have the right to  nullify  such
Company  Exercise Notice if any of the conditions set forth in this Section 4(b)
shall not have been met on each date  during the entire  period  referred  to in
clause (i) above. The Company covenants and agrees that it will

                                       3
<PAGE>

honor all  Exercise  Notices  tendered  from the time of delivery of the Company
Exercise Notice through 6:30 p.m.  (California time) on the Trading Day prior to
the Company Exercise Date.  Notwithstanding  the foregoing,  the Company and the
Holder  agree  that,  if and to the  extent  Section  11 of this  Warrant  would
restrict the right of the Company to issue or the right of the Holder to receive
any of the Warrant Shares otherwise issuable upon the conversion in respect of a
Company Exercise Notice, then notwithstanding anything to the contrary set forth
in the Company  Exercise  Notice,  the Company  Exercise  Notice shall be deemed
automatically  amended  to apply only to such  portion of this  Warrant as would
permit exercise in full in compliance with Section 11.2 The Holder will promptly
(and, in any event,  prior to the Company  Exercise  Date) notify the Company in
writing  following  receipt  of a Company  Exercise  Notice if  Section 11 would
restrict  its right to receive the full  number of  otherwise  issuable  Warrant
Shares following such Company Exercise Notice.  Subject to the foregoing,  if by
the tenth Trading Day  following  the Company  Exercise Date this Warrant is not
exercised in full, it shall expire as of such date.

      5. Delivery of Warrant Shares.

            (a) To effect exercises hereunder,  the Holder shall not be required
to  physically  surrender  this  Warrant  unless the  aggregate  Warrant  Shares
represented  by this Warrant is being  exercised.  Upon delivery of the Exercise
Notice (in the form attached  hereto) to the Company (with the attached  Warrant
Shares Exercise Log) at its address for notice set forth herein and upon payment
of the Exercise Price multiplied by the number of Warrant Shares that the Holder
intends to purchase hereunder, the Company shall promptly (but in no event later
than three  Trading Days after the Date of Exercise (as defined  herein))  issue
and deliver to the Holder,  a certificate  for the Warrant Shares  issuable upon
such exercise, which, unless otherwise required by the Purchase Agreement, shall
be free of restrictive  legends.  The Company shall,  upon request of the Holder
and subsequent to the date on which a registration statement covering the resale
of the Warrant Shares has been declared effective by the Securities and Exchange
Commission,  use its reasonable best efforts to deliver Warrant Shares hereunder
electronically  through the Depository Trust Corporation or another  established
clearing corporation performing similar functions, if available, provided, that,
the Company may,  but will not be required to change its  transfer  agent if its
current transfer agent cannot deliver Warrant Shares electronically  through the
Depository Trust  Corporation.  A "DATE OF EXERCISE" means the date on which the
Holder shall have  delivered to the Company:  (i) the Exercise  Notice (with the
Warrant  Exercise Log attached to it),  appropriately  completed and duly signed
and (ii) if such Holder is not utilizing the cashless  exercise  provisions  set
forth in this Warrant,  payment of the Exercise  Price for the number of Warrant
Shares so indicated by the Holder to be purchased.

            (b) If by the third Trading Day after a Date of Exercise the Company
fails to deliver the required  number of Warrant  Shares in the manner  required
pursuant to Section  5(a),  then the Holder will have the right to rescind  such
exercise.


------------------------------
2 This sentence will not appear in the Marr warrant.

                                       4
<PAGE>

            (c) If by the third Trading Day after a Date of Exercise the Company
fails to deliver the required  number of Warrant  Shares in the manner  required
pursuant to Section  5(a),  and if after such third Trading Day and prior to the
receipt  of such  Warrant  Shares,  the  Holder  purchases  (in an  open  market
transaction or otherwise) shares of Common Stock to deliver in satisfaction of a
sale by the Holder of the Warrant Shares which the Holder anticipated  receiving
upon such exercise (a  "BUY-IN"),  then the Company shall (1) pay in cash to the
Holder the amount by which (x) the  Holder's  total  purchase  price  (including
brokerage  commissions,  if any) for the  shares  of Common  Stock so  purchased
exceeds (y) the amount  obtained by multiplying (A) the number of Warrant Shares
that the Company was  required to deliver to the Holder in  connection  with the
exercise at issue by (B) the  closing bid price of the Common  Stock on the Date
of Exercise and (2) at the option of the Holder, either reinstate the portion of
the Warrant and equivalent  number of Warrant Shares for which such exercise was
not  honored or deliver to the Holder the number of shares of Common  Stock that
would have been issued had the Company  timely  complied  with its  exercise and
delivery  obligations  hereunder.  The Holder shall provide the Company  written
notice indicating the amounts payable to the Holder in respect of the Buy-In.

            (d) The Company's obligations to issue and deliver Warrant Shares in
accordance with the terms hereof are absolute and unconditional, irrespective of
any action or inaction by the Holder to enforce the same,  any waiver or consent
with respect to any provision  hereof,  the recovery of any judgment against any
Person  or  any  action  to  enforce  the  same,  or any  setoff,  counterclaim,
recoupment,  limitation or  termination,  or any breach or alleged breach by the
Holder or any other Person of any  obligation to the Company or any violation or
alleged violation of law by the Holder or any other Person,  and irrespective of
any other  circumstance  which  might  otherwise  limit such  obligation  of the
Company to the Holder in connection with the issuance of Warrant Shares. Nothing
herein shall limit a Holder's right to pursue any other remedies available to it
hereunder,  at law or in  equity  including,  without  limitation,  a decree  of
specific  performance  and/or  injunctive  relief with respect to the  Company's
failure to timely deliver certificates representing Warrant Shares upon exercise
of the Warrant as required pursuant to the terms hereof.

      6. Charges,  Taxes and Expenses.  Issuance and delivery of Warrant  Shares
upon exercise of this Warrant shall be made without charge to the Holder for any
issue or transfer tax,  withholding tax,  transfer agent fee or other incidental
tax or expense in respect of the  issuance  of such  certificates,  all of which
taxes and expenses  shall be paid by the Company;  provided,  however,  that the
Company  shall not be required to pay any tax which may be payable in respect of
any transfer involved in the registration of any certificates for Warrant Shares
or  Warrants  in a name  other  than that of the  Holder.  The  Holder  shall be
responsible for all other tax liability that may arise as a result of holding or
transferring this Warrant or receiving Warrant Shares upon exercise hereof.

      7. Replacement of Warrant.  If this Warrant is mutilated,  lost, stolen or
destroyed,  the  Company  shall  issue or cause to be  issued  in  exchange  and
substitution for and upon  cancellation  hereof,  or in lieu of and substitution
for this Warrant,  a New Warrant,  but only upon receipt of evidence  reasonably
satisfactory to the Company of such loss, theft or destruction and customary and
reasonable  indemnity  (which shall not include a surety  bond),  if  requested.
Applicants  for a New Warrant  under such  circumstances  shall also comply with
such other  reasonable  regulations and procedures and pay such other reasonable
third-party costs as the Company may prescribe. If a New Warrant is requested as
a result of a mutilation  of this  Warrant,  then the Holder shall  deliver such
mutilated  Warrant to the  Company as a  condition  precedent  to the  Company's
obligation to issue the New Warrant.

                                       5
<PAGE>

      8.  Reservation of Warrant Shares.  The Company  covenants that it will at
all times reserve and keep  available out of the aggregate of its authorized but
unissued  and  otherwise  unreserved  Common  Stock,  solely for the  purpose of
enabling  it to issue  Warrant  Shares upon  exercise of this  Warrant as herein
provided,  the number of Warrant Shares which are then issuable and  deliverable
upon the exercise of this entire  Warrant,  free from  preemptive  rights or any
other  contingent  purchase rights of Persons other than the Holder (taking into
account the  adjustments and  restrictions of Section 9). The Company  covenants
that all Warrant Shares so issuable and deliverable shall, upon issuance and the
payment of the applicable Exercise Price in accordance with the terms hereof, be
duly and validly authorized, issued and fully paid and nonassessable.

      9. Certain  Adjustments.  The Exercise  Price and number of Warrant Shares
issuable upon  exercise of this Warrant are subject to  adjustment  from time to
time as set forth in this Section 9.

            (a) Stock  Dividends and Splits.  If the Company,  at any time while
this Warrant is  outstanding,  (i) pays a stock  dividend on its Common Stock or
otherwise  makes a distribution on any class of capital stock that is payable in
shares of Common Stock, (ii) subdivides  outstanding shares of Common Stock into
a larger number of shares, or (iii) combines  outstanding shares of Common Stock
into a smaller number of shares, then in each such case the Exercise Price shall
be multiplied by a fraction of which the numerator shall be the number of shares
of Common  Stock  outstanding  immediately  before  such  event and of which the
denominator   shall  be  the  number  of  shares  of  Common  Stock  outstanding
immediately after such event. Any adjustment made pursuant to clause (i) of this
paragraph  shall  become  effective  immediately  after the record  date for the
determination of stockholders entitled to receive such dividend or distribution,
and any  adjustment  pursuant  to clause (ii) or (iii) of this  paragraph  shall
become  effective  immediately  after the effective date of such  subdivision or
combination.

            (b) Fundamental Transactions.  If, at any time while this Warrant is
outstanding there is a Fundamental  Transaction,  then the Holder shall have the
right thereafter to receive,  upon exercise of this Warrant, the same amount and
kind of  securities,  cash or property as it would have been entitled to receive
upon the occurrence of such Fundamental  Transaction if it had been, immediately
prior to such  Fundamental  Transaction,  the  holder of the  number of  Warrant
Shares then  issuable  upon  exercise in full of this  Warrant  (the  "ALTERNATE
CONSIDERATION").  For purposes of any such exercise,  the  determination  of the
Exercise  Price  shall be  appropriately  adjusted  to  apply to such  Alternate
Consideration based on the amount of Alternate Consideration issuable in respect
of one share of Common Stock in such  Fundamental  Transaction,  and the Company
shall  apportion  the  Exercise  Price among the  Alternate  Consideration  in a
reasonable manner  reflecting the relative value of any different  components of
the Alternate Consideration.  If holders of Common Stock are given any choice as
to the securities, cash or property to be received in a Fundamental Transaction,
then the Holder shall be given the same choice as to the Alternate Consideration
it  receives  upon any  exercise  of this  Warrant  following  such  Fundamental
Transaction. At the Holder's option and request, any successor to the Company or
surviving entity in such Fundamental  Transaction shall, either (1) issue to the


                                       6
<PAGE>

Holder a new warrant  substantially  in the form of this Warrant and  consistent
with the foregoing  provisions and evidencing the Holder's right to purchase the
Alternate  Consideration for the aggregate Exercise Price upon exercise thereof,
or (2)  purchase the Warrant  from the Holder for a purchase  price,  payable in
cash within five Trading Days after such request (or, if later, on the effective
date of the  Fundamental  Transaction),  equal to the Black Scholes value of the
remaining  unexercised portion of this Warrant on the date of such request.  The
terms of any agreement  pursuant to which a Fundamental  Transaction is effected
shall include terms  requiring any such successor or surviving  entity to comply
with the  provisions of this paragraph (c) and insuring that the Warrant (or any
such  replacement  security)  will be  similarly  adjusted  upon any  subsequent
transaction analogous to a Fundamental Transaction.

            (c) Number of Warrant Shares.  Simultaneously with any adjustment to
the Exercise  Price  pursuant to Section 9(a), the number of Warrant Shares that
may be purchased  upon  exercise of this Warrant shall be increased or decreased
proportionately,  so that after such  adjustment  the aggregate  Exercise  Price
payable hereunder for the adjusted number of Warrant Shares shall be the same as
the aggregate Exercise Price in effect immediately prior to such adjustment.

            (d)  Calculations.  All  calculations  under this Section 9 shall be
made to the nearest cent or the nearest 1/100th of a share,  as applicable.  The
number of shares of Common Stock outstanding at any given time shall not include
shares owned or held by or for the account of the Company,  and the  disposition
of any such shares shall be considered an issue or sale of Common Stock.

            (e) Notice of  Adjustments.  Upon the occurrence of each  adjustment
pursuant to this  Section 9, the Company at its expense  will  promptly  compute
such  adjustment  in  accordance  with the terms of this  Warrant  and prepare a
certificate setting forth such adjustment, including a statement of the adjusted
Exercise Price and adjusted number or type of Warrant Shares or other securities
issuable  upon  exercise  of  this  Warrant  (as  applicable),   describing  the
transactions  giving  rise to such  adjustments  and showing in detail the facts
upon which such  adjustment  is based.  Upon written  request,  the Company will
promptly  deliver  a copy of each  such  certificate  to the  Holder  and to the
Company's Transfer Agent.

            (f)  Notice of  Corporate  Events.  If the  Company  (i)  declares a
dividend or any other  distribution  of cash,  securities  or other  property in
respect of its Common Stock, including without limitation any granting of rights
or warrants to subscribe for or purchase any capital stock of the Company or any
Subsidiary, (ii) authorizes or approves, enters into any agreement contemplating
or  solicits  stockholder  approval  for any  Fundamental  Transaction  or (iii)
authorizes the voluntary  dissolution,  liquidation or winding up of the affairs
of the Company, then the Company shall deliver to the Holder a notice describing
the material  terms and conditions of such  transaction  (but only to the extent
such disclosure would not result in the  dissemination  of material,  non-public
information  to the  Holder) at least 10 calendar  days prior to the  applicable
record or  effective  date on which a Person  would need to hold Common Stock in
order to  participate  in or vote  with  respect  to such  transaction,  and the
Company  will take all steps  reasonably  necessary  in order to insure that the
Holder is given the practical opportunity to exercise this Warrant prior to such
time so as to participate in or vote with respect to such transaction; provided,
however, that the failure to deliver such notice or any defect therein shall not
affect the  validity of the  corporate  action  required to be described in such
notice.

                                       7
<PAGE>

      10.  Payment of Exercise  Price.  The Holder may pay the Exercise Price in
one of the following manners:

            (a) Cash  Exercise.  The Holder may  deliver  immediately  available
funds; or

            (b) Cashless Exercise.  If an Exercise Notice is delivered at a time
when a registration statement permitting the Holder to resell the Warrant Shares
is not then  effective  or the  prospectus  forming a part  thereof  is not then
available  to the Holder for the resale of the Warrant  Shares,  then the Holder
may notify the Company in an Exercise Notice of its election to utilize cashless
exercise,  in which  event the  Company  shall issue to the Holder the number of
Warrant Shares determined as follows:

                  X = Y [(A-B)/A]

         where:

                  X = the number of Warrant Shares to be issued to the Holder.

                  Y  =  the  number  of  Warrant  Shares  with
                  respect  to  which  this  Warrant  is  being
                  exercised.

                  A = the  average of the  closing  prices for
                  the five Trading Days  immediately  prior to
                  (but not including) the Exercise Date.

                  B = the Exercise Price.

For purposes of Rule 144  promulgated  under the Securities Act, it is intended,
understood  and  acknowledged  that the  Warrant  Shares  issued  in a  cashless
exercise  transaction  shall be deemed to have been acquired by the Holder,  and
the holding period for the Warrant Shares shall be deemed to have commenced,  on
the Original Issue Date.

      11.  Limitations  on  Exercise.  Notwithstanding  anything to the contrary
contained  herein,  the number of Warrant  Shares  that may be  acquired  by the
Holder upon any exercise of this Warrant (or otherwise in respect  hereof) shall
be limited to the extent  necessary to insure that,  following such exercise (or
other  issuance),  the total number of shares of Common Stock then  beneficially
owned by such Holder and its Affiliates  and any other Persons whose  beneficial
ownership of Common Stock would be aggregated  with the Holder's for purposes of
Section 13(d) of the Exchange Act, does not exceed 9.999% of the total number of
issued and  outstanding  shares of Common Stock  (including for such purpose the
shares  of  Common  Stock  issuable  upon  such  exercise).  For such  purposes,
beneficial ownership shall be determined in accordance with Section 13(d) of the
Exchange  Act  and  the  rules  and  regulations  promulgated  thereunder.  This
provision shall not restrict the number of shares of Common Stock which a Holder
may receive or  beneficially  own in order to determine the amount of securities
or  other  consideration  that  such  Holder  may  receive  in  the  event  of a
Fundamental  Transaction  as  contemplated  in Section 9 of this  Warrant.  This
restriction may not be waived.(3)
---------------
(3) This provision will not appear in the Marr warrant.

                                       8
<PAGE>

      12. No Fractional  Shares.  No fractional shares of Warrant Shares will be
issued  in  connection  with  any  exercise  of  this  Warrant.  In  lieu of any
fractional shares which would, otherwise be issuable, the Company shall pay cash
equal to the product of such  fraction  multiplied  by the closing  price of one
Warrant  Share as  reported  by the  applicable  Trading  Market  on the date of
exercise.

      13.  Notices.  Any and all notices or other  communications  or deliveries
hereunder  (including,  without  limitation,  any Exercise  Notice)  shall be in
writing and shall be deemed given and  effective on the earliest of (i) the date
of  transmission,  if such notice or communication is delivered via facsimile at
the facsimile number specified in this Section prior to 6:30 p.m. (New York City
time)  on  a  Trading  Day,  (ii)  the  next  Trading  Day  after  the  date  of
transmission,  if such notice or communication is delivered via facsimile at the
facsimile number specified in this Section on a day that is not a Trading Day or
later than 6:30 p.m. (New York City time) on any Trading Day,  (iii) the Trading
Day following the date of mailing,  if sent by nationally  recognized  overnight
courier service, or (iv) upon actual receipt by the party to whom such notice is
required to be given. The addresses for such communications  shall be: (i) if to
the Company, to Calypte Biomedical Corporation, Attn: President, or to Facsimile
No.:  (925)  730-0146 (or such other  address as the Company  shall  indicate in
writing in  accordance  with this  Section),  or (ii) if to the  Holder,  to the
address or  facsimile  number  appearing  on the Warrant  Register or such other
address  or  facsimile  number as the  Holder  may  provide  to the  Company  in
accordance with this Section.

      14.  Warrant  Agent.  The Company  shall serve as warrant agent under this
Warrant.  Upon 10 days'  notice to the  Holder,  the  Company  may appoint a new
warrant agent.  Any corporation  into which the Company or any new warrant agent
may be merged or any corporation  resulting from any  consolidation to which the
Company or any new warrant  agent shall be a party or any  corporation  to which
the  Company  or  any  new  warrant  agent  transfers  substantially  all of its
corporate trust or shareholders  services  business shall be a successor warrant
agent under this Warrant  without any further act.  Any such  successor  warrant
agent shall  promptly  cause  notice of its  succession  as warrant  agent to be
mailed (by first class mail, postage prepaid) to the Holder at the Holder's last
address as shown on the Warrant Register.

      15. Miscellaneous.

            (a) This Warrant shall be binding on and inure to the benefit of the
parties  hereto and their  respective  successors  and  assigns.  Subject to the
preceding  sentence,  nothing in this Warrant  shall be construed to give to any
Person  other than the  Company  and the Holder  any legal or  equitable  right,
remedy or cause of action under this  Warrant.  This Warrant may be amended only
in  writing  signed by the  Company  and the  Holder  and their  successors  and
assigns.


                                       9
<PAGE>

            (b) All questions concerning the construction, validity, enforcement
and  interpretation  of this  Warrant  shall be  governed by and  construed  and
enforced in  accordance  with the internal laws of the State of New York (except
for matters governed by corporate law in the State of Delaware),  without regard
to the principles of conflicts of law thereof.  Each party agrees that all legal
proceedings  concerning  the  interpretations,  enforcement  and defense of this
Warrant  and  the  transactions  herein  contemplated  ("PROCEEDINGS")  (whether
brought  against  a party  hereto or its  respective  Affiliates,  employees  or
agents) shall be commenced exclusively in the New York Courts. Each party hereto
hereby irrevocably submits to the exclusive  jurisdiction of the New York Courts
for the adjudication of any dispute hereunder or in connection  herewith or with
any transaction  contemplated hereby or discussed herein, and hereby irrevocably
waives,  and  agrees not to assert in any  Proceeding,  any claim that it is not
personally  subject  to the  jurisdiction  of any New York  Court,  or that such
Proceeding has been commenced in an improper or inconvenient  forum.  Each party
hereto hereby  irrevocably  waives  personal  service of process and consents to
process  being  served in any such  Proceeding  by  mailing a copy  thereof  via
registered or certified  mail or overnight  delivery (with evidence of delivery)
to such party at the address in effect for notices to it under this  Warrant and
agrees that such service shall constitute good and sufficient service of process
and notice thereof. Nothing contained herein shall be deemed to limit in any way
any right to serve  process in any manner  permitted  by law.  Each party hereto
hereby  irrevocably  waives,  to the fullest extent permitted by applicable law,
any and all right to trial by jury in any  legal  proceeding  arising  out of or
relating to this  Warrant or the  transactions  contemplated  hereby.  If either
party shall  commence a Proceeding  to enforce any  provisions  of this Warrant,
then the prevailing  party in such  Proceeding  shall be reimbursed by the other
party for its  attorney's  fees and other costs and expenses  incurred  with the
investigation, preparation and prosecution of such Proceeding.

            (c) The headings herein are for convenience  only, do not constitute
a part of this  Warrant  and shall  not be deemed to limit or affect  any of the
provisions hereof.

            (d) In case any one or more of the  provisions of this Warrant shall
be invalid or unenforceable in any respect,  the validity and  enforceability of
the  remaining  terms and  provisions  of this  Warrant  shall not in any way be
affected or impaired thereby and the parties will attempt in good faith to agree
upon a valid and enforceable provision which shall be a commercially  reasonable
substitute  therefor,  and upon so agreeing,  shall  incorporate such substitute
provision in this Warrant.

            (e) Prior to exercise of this Warrant,  the Holder hereof shall not,
by reason of being a Holder,  be  entitled to any rights of a  stockholder  with
respect to the Warrant Shares.

                  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK,
                             SIGNATURE PAGE FOLLOWS]


                                       10
<PAGE>

      IN  WITNESS  WHEREOF,  the  Company  has  caused  this  Warrant to be duly
executed by its authorized officer as of the date first indicated above.

                                       CALYPTE BIOMEDICAL CORPORATION

                                       By:
                                          --------------------------------------
                                          Name:  Richard D. Brounstein
                                          Title: EVP and CFO


                                       11
<PAGE>

                                 EXERCISE NOTICE
                         CALYPTE BIOMEDICAL CORPORATION
                           WARRANT DATED APRIL 4, 2005

The  undersigned  Holder  hereby  irrevocably  elects to purchase  _____________
shares of Common Stock  pursuant to the above  referenced  Warrant.  Capitalized
terms used herein and not  otherwise  defined have the  respective  meanings set
forth in the Warrant.

(1)  The   undersigned   Holder   hereby   exercises   its  right  to   purchase
_________________ Warrant Shares pursuant to the Warrant.

(2) The Holder  intends  that  payment of the  Exercise  Price  shall be made as
(check one):

                       ____"Cash Exercise" under Section 10

                       ____"Cashless Exercise" under Section 10

(3) If the holder has elected a Cash  Exercise,  the holder shall pay the sum of
$____________ to the Company in accordance with the terms of the Warrant.

(4) Pursuant to this  Exercise  Notice,  the Company shall deliver to the holder
_______________ Warrant Shares in accordance with the terms of the Warrant.

(5) By its delivery of this Exercise  Notice,  the  undersigned  represents  and
warrants to the Company that in giving effect to the exercise  evidenced  hereby
the Holder will not beneficially own in excess of the number of shares of Common
Stock  (determined in accordance  with Section 13(d) of the Securities  Exchange
Act of 1934)  permitted  to be owned under  Section 11 of this  Warrant to which
this notice relates.

Dated:                                          Name of Holder:
       ---------------------,  -------

                                                (Print)

                                                By:
                                                Name:
                                                Title:

                                                (Signature  must  conform in all
                                                respects  to  name of  holder as
                                                specified  on  the face  of  the
                                                Warrant)


                                       12
<PAGE>

<TABLE>
<CAPTION>

                                            Warrant Shares Exercise Log

----------------------------- -----------------------------   ---------------------------------- ---------------------
<S>                          <C>                             <C>                                <C>
Date                          Number  of  Warrant   Shares    Number of Warrant Shares           Number  of   Warrant
                              Available to be Exercised       Exercised                          Shares  Remaining to
                                                                                                 be Exercised

----------------------------- -----------------------------   ---------------------------------- ---------------------








----------------------------- ----------------------------- ---------------------------------- ---------------------

</TABLE>

                                       13
<PAGE>

                         CALYPTE BIOMEDICAL CORPORATION
                     WARRANT ORIGINALLY ISSUED APRIL 4, 2005
                                 WARRANT NO. [ ]


                               FORM OF ASSIGNMENT


      [To be completed and signed only upon transfer of Warrant]

      FOR VALUE RECEIVED,  the undersigned  hereby sells,  assigns and transfers
unto    ________________________________    the   right   represented   by   the
above-captioned Warrant to purchase ____________ shares of Common Stock to which
such Warrant  relates and appoints  ________________  attorney to transfer  said
right on the  books of the  Company  with  full  power  of  substitution  in the
premises.

Dated:   _______________, ____

                            ----------------------------------------------------
                            (Signature  must  conform in all respects to name of
                            holder as specified on the face of the Warrant)



                            ----------------------------------------------------
                            Address of Transferee

                            ----------------------------------------------------


                            ----------------------------------------------------


In the presence of:


--------------------------



                                       14