LETTER OF TRANSMITTAL

                          MOLECULAR DIAGNOSTICS, INC.

                               OFFER TO EXCHANGE
                  800,000 SERIES E CONVERTIBLE PREFERRED STOCK
          PURSUANT TO THE OFFERING CIRCULAR, DATED NOVEMBER 19, 2001,
                                   FOR UP TO
                       20,000,000 SHARES OF COMMON STOCK

        THE EXCHANGE OFFER WILL EXPIRE AT 5:00 P.M., NEW YORK CITY TIME,
          ON DECEMBER 19, 2001, UNLESS EXTENDED OR EARLIER TERMINATED.
        TENDERS MAY BE WITHDRAWN PRIOR TO 5:00 P.M., NEW YORK CITY TIME,
                            ON THE EXPIRATION DATE.

                             The Exchange Agent is:
                       LASALLE BANK NATIONAL ASSOCIATION

<Table>
                                                                
        By Certified Mail:               By Overnight Courier:                     By Hand:
LaSalle Bank National Association  LaSalle Bank National Association  LaSalle Bank National Association
 135 South LaSalle Street, Suite    135 South LaSalle Street, Suite    135 South LaSalle Street, Suite
               1960                               1960                               1960
     Chicago, Illinois 60603            Chicago, Illinois 60603            Chicago, Illinois 60603
      Attention: Mark Rimkus             Attention: Mark Rimkus             Attention: Mark Rimkus
  (registered or certified mail
           recommended)
</Table>

                                 By Facsimile:
                     (Eligible Guarantor Institutions Only)
                                 (312) 904-2236

                            To Confirm by Telephone
                            or for Information Call:
                                 (312) 904-2458
                             ---------------------
        DELIVERY OF THIS LETTER OF TRANSMITTAL TO AN ADDRESS OTHER THAN
        THOSE LISTED ABOVE, OR TRANSMISSION OF INSTRUCTIONS BY FACSIMILE
           OTHER THAN AS SET FORTH ABOVE,WILL NOT CONSTITUTE A VALID
                         DELIVERY OF YOUR COMMON STOCK.


     By signing this Letter of Transmittal, you hereby acknowledge that you have
received the Offering Circular, dated December 18, 2001 (the "Offering
Circular"), of Molecular Diagnostics, Inc. ("Molecular Diagnostics") and this
Letter of Transmittal. The Offering Circular, together with this Letter of
Transmittal, constitutes Molecular Diagnostics' offer to exchange (the "Exchange
Offer") 1/25 (one twenty-fifth) of a share of Series E convertible preferred
stock, par value $0.001, of Molecular Diagnostics, for each share of common
stock, par value $0.001, of Molecular Diagnostics, currently outstanding.
Subject to the terms and conditions of the Exchange Offer, Molecular Diagnostics
will issue 800,000 shares of Series E convertible preferred stock in exchange
for up to 20,000,000 shares of common stock, representing approximately 56% of
the outstanding common stock as of November 16, 2001 that is properly tendered
and not withdrawn prior to the expiration of the Exchange Offer. If more than
20,000,000 shares of common stock are tendered, Molecular Diagnostics will
purchase from each tendering holder of common stock an amount based on the
proportion of common stock tendered by that holder to all common stock tendered.
Molecular Diagnostics reserves the right to terminate or amend the Exchange
Offer, in its sole and absolute discretion, if any of the conditions listed in
the section of the Offering Circular entitled "The Exchange Offer -- Conditions
to the Exchange Offer" are not satisfied or waived prior to the expiration of
the Exchange Offer. Molecular Diagnostics also reserves the right, in its sole
and absolute discretion, to extend the period of time during which the Exchange
Offer is open. The Exchange Offer is open to all holders of common stock, and is
subject to customary conditions. Subject to applicable


                                        1



securities laws and the terms set forth in the Offering Circular, Molecular
Diagnostics reserves the right to waive any and all conditions other than
receipt of necessary government approvals on or before the expiration of the
Exchange Offer.


     If you decide to tender your common stock, and Molecular Diagnostics
accepts the common stock, this will constitute a binding agreement between you
and Molecular Diagnostics, subject to the terms and conditions set forth in the
Offering Circular and this Letter of Transmittal. Unless you comply with the
procedures described in the section of the Offering Circular entitled "The
Exchange Offer -- Guaranteed Delivery Procedures," you must do one of the
following prior to the expiration of the Exchange Offer to participate in the
Exchange Offer:

     - tender your common stock by sending the certificates representing your
       common stock, in proper form for transfer, a properly completed and duly
       executed Letter of Transmittal, with any required signature guarantees,
       and all other documents required by this Letter of Transmittal to the
       Exchange Agent at one of the addresses listed above; or

     - tender your common stock by using the book-entry transfer procedures
       described in the section of the Offering Circular entitled "The Exchange
       Offer -- Book-Entry Transfer," and transmitting this Letter of
       Transmittal, with any required signature guarantees, or an Agent's
       Message (as defined below) instead of this Letter of Transmittal to the
       Exchange Agent.

     In order for a book-entry transfer to constitute a valid tender of your
common stock in the Exchange Offer, the Exchange Agent must receive a
confirmation of book-entry transfer (a "Book-Entry Confirmation") of your common
stock into the Exchange Agent's account at The Depository Trust Company prior to
the expiration of the Exchange Offer. The term "Agent's Message" means a
message, transmitted by The Depository Trust Company and received by the
Exchange Agent and forming a part of the Book-Entry Confirmation, which states
that The Depository Trust Company has received an express acknowledgment from
you that you have received and have agreed to be bound by the terms of this
Letter of Transmittal. If you use this procedure, we may enforce the Letter of
Transmittal against you.

       DELIVERY OF DOCUMENTS TO THE DEPOSITORY TRUST COMPANY'S BOOK-ENTRY
     TRANSFER FACILITY WILL NOT CONSTITUTE DELIVERY TO THE EXCHANGE AGENT.

     If you wish to tender common stock in the Exchange Offer, but (1) the
certificates representing your common stock are not immediately available, (2)
time will not permit the certificates or other required documents to reach the
Exchange Agent before the expiration of the Exchange Offer, or (3) the procedure
for book-entry transfer cannot be completed before the expiration of the
Exchange Offer, you may tender the common stock by following the procedures
described in the section of the Offering Circular entitled "The Exchange
Offer -- Guaranteed Delivery Procedures."

     Only registered holders of the common stock -- which term, for purposes of
this Letter of Transmittal, includes any participant in The Depository Trust
Company's system whose name appears on a security position listing as the owner
of the common stock -- are entitled to tender their common stock for exchange in
the Exchange Offer. If you are a beneficial owner whose common stock is
registered in the name of a broker, dealer, commercial bank, trust company or
other nominee and you wish to tender your common stock in the Exchange Offer,
you should promptly contact the person in whose name the common stock is
registered and instruct that person to tender on your behalf. If you wish to
tender in the Exchange Offer on your own behalf, prior to completing and
executing this Letter of Transmittal and delivering the certificates
representing your common stock, you must either make appropriate arrangements to
register ownership of the common stock in your name or obtain a properly
completed endorsement or executed stock powers from the person in whose name the
common stock is registered.

     YOU MUST COMPLETE THIS LETTER OF TRANSMITTAL IF YOU ARE A REGISTERED HOLDER
OF COMMON STOCK -- WHICH TERM, FOR PURPOSES OF THIS LETTER OF TRANSMITTAL,
INCLUDES ANY PARTICIPANT IN THE DEPOSITORY TRUST COMPANY'S SYSTEM WHOSE NAME
APPEARS ON A SECURITY POSITION LISTING AS THE OWNER OF THE COMMON STOCK -- AND
EITHER (1) YOU WISH TO TENDER THE CERTIFICATES

                                        2


REPRESENTING YOUR COMMON STOCK TO THE EXCHANGE AGENT TOGETHER WITH THIS LETTER
OF TRANSMITTAL OR (2) YOU WISH TO TENDER YOUR COMMON STOCK BY BOOK-ENTRY
TRANSFER TO THE EXCHANGE AGENT'S ACCOUNT AT THE DEPOSITORY TRUST COMPANY AND YOU
ELECT TO SUBMIT THIS LETTER OF TRANSMITTAL TO THE EXCHANGE AGENT INSTEAD OF AN
AGENT'S MESSAGE.

     In order to properly complete this Letter of Transmittal, you must: (1)
complete the box entitled "Description of Common Stock," (2) if appropriate,
check and complete the boxes relating to book-entry transfer and guaranteed
delivery and the boxes entitled "Special Issuance Instructions" and "Special
Delivery Instructions" and (3) sign this Letter of Transmittal by completing the
box entitled "Sign Here." By completing the box entitled "Description of Common
Stock" and signing below, you will have tendered your common stock for exchange
on the terms and conditions described in the Offering Circular and this Letter
of Transmittal. You should read the detailed instructions below before
completing this Letter of Transmittal.

                                        3


                    NOTE: SIGNATURES MUST BE PROVIDED BELOW
              PLEASE READ THE ACCOMPANYING INSTRUCTIONS CAREFULLY

       BOX BELOW TO BE COMPLETED BY ALL TENDERING HOLDERS OF COMMON STOCK

<Table>
<Caption>
- ------------------------------------------------------------------------------------------------------------
                                    DESCRIPTION OF COMMON STOCK TENDERED
- ------------------------------------------------------------------------------------------------------------
                                                          1                   2                   3
                                                 -----------------------------------------------------------
                NAME AND ADDRESS                     CERTIFICATE          AMOUNT OF            AMOUNT
              OF REGISTERED HOLDER                   NUMBER(S)*         COMMON STOCK         TENDERED**
- ------------------------------------------------------------------------------------------------------------
                                                                                

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

                                                       TOTAL:
- ------------------------------------------------------------------------------------------------------------
  * Need not be completed by holders who tender by book-entry transfer.
 ** Unless otherwise indicated in column 3, a holder will be deemed to have tendered ALL of the common stock
    represented by the certificate(s) listed in column 1. See Instruction 4.
- ------------------------------------------------------------------------------------------------------------
</Table>

                    BOXES BELOW TO BE CHECKED AS APPLICABLE

[ ]  CHECK HERE IF THE CERTIFICATE(S) REPRESENTING YOUR COMMON STOCK IS BEING
     TENDERED WITH THIS LETTER OF TRANSMITTAL.

[ ]  CHECK HERE IF THE CERTIFICATE(S) REPRESENTING YOUR COMMON STOCK HAS BEEN
     LOST, DESTROYED OR STOLEN AND YOU REQUIRE ASSISTANCE IN OBTAINING A NEW
     CERTIFICATE(S).

     Certificate Number(s)
- ------------------------------------------------------------------------------

     Amount(s) Represented
- ----------------------------------------------------------------------------

     You must contact the Exchange Agent to obtain instructions for replacing
     lost, destroyed or stolen certificate(s) representing common stock. See
     Instruction 11.

                                        4


                    BOXES BELOW TO BE CHECKED AS APPLICABLE

                         SPECIAL ISSUANCE INSTRUCTIONS
                         (SEE INSTRUCTIONS 1, 5 AND 6)

     To be completed ONLY if common stock not tendered or exchanged or Series E
convertible preferred stock is to be issued in the name of someone other than
the registered holder of the common stock whose name(s) appear(s) below.

[  ] Common Stock to:
[  ] Series E Convertible Preferred Stock to:

Name ---------------------------------------------------------------------------
                                    (PLEASE PRINT)

Address ------------------------------------------------------------------------
- --------------------------------------------------------------------------------
                                   (ZIP CODE)

Telephone Number  (     )     -
                     -----------------------------------------------------------
- --------------------------------------------------------------------------------
                             (TAX IDENTIFICATION OR
                              SOCIAL SECURITY NO.)
                              (SEE INSTRUCTION 13)

                         SPECIAL DELIVERY INSTRUCTIONS
                         (SEE INSTRUCTIONS 1, 5 AND 6)

     To be completed ONLY if common stock not tendered or exchanged or Series E
convertible preferred stock is to be delivered to someone other than the
registered holder of the common stock whose name(s) appear(s) below or to the
registered holder at an address other than shown below.

[  ] Common Stock to:
[  ] Series E Convertible Preferred Stock to:

Name ---------------------------------------------------------------------------
                                    (PLEASE PRINT)

Address ------------------------------------------------------------------------
- --------------------------------------------------------------------------------
                                   (ZIP CODE)

Telephone Number  (     )     -
                     -----------------------------------------------------------
- --------------------------------------------------------------------------------
                             (TAX IDENTIFICATION OR
                              SOCIAL SECURITY NO.)
                              (SEE INSTRUCTION 13)

[ ] CHECK HERE AND ENCLOSE A PHOTOCOPY OF THE NOTICE OF GUARANTEED DELIVERY IF
    TENDERED COMMON STOCK IS BEING DELIVERED UNDER A NOTICE OF GUARANTEED
    DELIVERY PREVIOUSLY SENT TO THE EXCHANGE AGENT AND COMPLETE THE FOLLOWING:

   Name(s) of Registered Holder(s) ---------------------------------------------

   Window Ticket Number (if any) -----------------------------------------------

   Date of Execution of Notice of Guaranteed Delivery --------------------------

   Name of Institution which Guaranteed Delivery -------------------------------

           If delivered by book-entry transfer, complete the following:

   Name of Tendering Institution -----------------------------------------------

   Account Number --------------------------------------------------------------

   Transaction Code Number -----------------------------------------------------

                                        5


            BOXES BELOW TO BE CHECKED BY ELIGIBLE INSTITUTIONS ONLY

[ ] CHECK HERE IF TENDERED COMMON STOCK IS BEING DELIVERED BY BOOK-ENTRY
    TRANSFER TO THE EXCHANGE AGENT'S ACCOUNT AT THE DEPOSITORY TRUST COMPANY AND
    COMPLETE THE FOLLOWING:

   Name of Tendering Institution -----------------------------------------------

   Account Number --------------------------------------------------------------

   Transaction Code Number -----------------------------------------------------

[ ] CHECK HERE IF THE COMMON STOCK THAT IS NOT TENDERED OR NOT EXCHANGED ARE TO
    BE RETURNED BY CREDITING THE DEPOSITORY TRUST COMPANY ACCOUNT NUMBER
    INDICATED ABOVE.

                                        6

Ladies and Gentlemen:

     Upon the terms and subject to the conditions of the Exchange Offer, as
described in the Offering Circular and this Letter of Transmittal, I hereby
tender to Molecular Diagnostics, Inc. the amount of common stock, described
above in the box entitled "Description of Common Stock Tendered," in exchange
for shares of Series E convertible preferred stock tendered for exchange.


     Subject to the terms and conditions of the Exchange Offer, Molecular
Diagnostics will issue 800,000 shares of Series E convertible preferred stock in
exchange for up to 20,000,000 shares of common stock representing approximately
56% of the outstanding shares of common stock as of November 16, 2001 that are
properly tendered and not withdrawn prior to the expiration of the Exchange
Offer. If more than 20,000,000 shares of common stock are tendered, Molecular
Diagnostics will purchase from each tendering holder of common stock an amount
based on the proportion of common stock tendered by that holder to all common
stock tendered. Molecular Diagnostics reserves the right to terminate or amend
the Exchange Offer, in its sole and absolute discretion, if any of the
conditions listed in the section of the Offering Circular entitled "The Exchange
Offer -- Conditions to the Exchange Offer" are not satisfied or waived prior to
expiration of the Exchange Offer. Molecular Diagnostics also reserves the right,
in its sole and absolute discretion, to extend the period of time during which
the Exchange Offer is open. The Exchange Offer is open to all holders of common
stock, and is subject to customary conditions. Subject to applicable securities
laws and the terms set forth in the Offering Circular, Molecular Diagnostics
reserves the right to waive any and all conditions other than receipt of
necessary government approvals on or before the expiration of the Exchange
Offer.


     Subject to and effective upon the acceptance for exchange of all or any
portion of the common stock tendered by this Letter of Transmittal in accordance
with the terms and conditions of the Exchange Offer -- including, if the
Exchange Offer is extended or amended, the terms and conditions of any extension
or amendment -- I hereby sell, assign and transfer to, or upon the order of,
Molecular Diagnostics all right, title and interest in and to the common stock
tendered by this Letter of Transmittal. I hereby irrevocably constitute and
appoint the Exchange Agent as my agent and attorney-in-fact -- with full
knowledge that the Exchange Agent is also acting as the agent of Molecular
Diagnostics in connection with the Exchange Offer -- with respect to the
tendered common stock, with full power of substitution, such power of attorney
being deemed to be an irrevocable power coupled with an interest, subject only
to the right of withdrawal described in the Offering Circular, to (1) deliver
certificates representing the tendered common stock to Molecular Diagnostics
together with all accompanying evidences of transfer and authenticity to, or
upon the order of, Molecular Diagnostics, upon receipt by the Exchange Agent, as
my agent, of the Series E convertible preferred stock to be issued in exchange
for the tendered common stock, (2) present certificates representing the
tendered common stock for transfer, and to transfer the tendered common stock on
the books of Molecular Diagnostics, and (3) receive for the account of Molecular
Diagnostics all benefits and otherwise exercise all rights of ownership of the
tendered common stock, all in accordance with the terms and conditions of the
Exchange Offer.

     I hereby represent and warrant that I have full power and authority to
tender, sell, assign and transfer the common stock tendered by this Letter of
Transmittal and that, when the tendered common stock is accepted for exchange,
Molecular Diagnostics will acquire good, marketable and unencumbered title to
the tendered common stock, free and clear of all liens, restrictions, charges
and encumbrances, and that the tendered common stock is not subject to any
adverse claims or proxies. I will, upon request, execute and deliver any
additional documents deemed by Molecular Diagnostics or the Exchange Agent to be
necessary or desirable to complete the exchange, sale, assignment and transfer
of the common stock tendered by this Letter of Transmittal. I agree to all of
the terms of the Exchange Offer.

     The name(s) and address(es) of the registered holder(s) -- which term, for
purposes of this Letter of Transmittal, includes any participant in The
Depository Trust Company's system whose name appears on a security position
listing as the holder of the common stock -- of the common stock tendered by
this Letter of Transmittal are printed above as they appear on the
certificate(s) representing the common stock. The certificate number(s) and the
common stock that I wish to tender are indicated in the appropriate boxes above.

     Unless I have otherwise indicated by completing the box entitled "Special
Issuance Instructions" above, I hereby direct that the Series E convertible
preferred stock be issued in the name(s) of the undersigned or, in

                                        7


the case of a book-entry transfer of common stock, that the Series E convertible
preferred stock be credited to the account indicated above maintained with The
Depository Trust Company. Similarly, unless I have otherwise indicated by
completing the box entitled "Special Delivery Instructions," I hereby direct
that the Series E convertible preferred stock be delivered to the address shown
below my signature.

     If I have (1) tendered any common stock that are not exchanged in the
Exchange Offer for any reason or (2) submitted certificates for more common
stock than I wish to tender, unless I have otherwise indicated by completing the
boxes entitled "Special Issuance Instructions" or "Special Delivery
Instructions," I hereby direct that certificates for any common stock that are
not tendered or not exchanged should be issued in the name of the undersigned,
if applicable, and delivered to the address shown below my signature or, in the
case of a book-entry transfer of common stock, that common stock that are not
tendered or not exchanged be credited to the account indicated above maintained
with The Depository Trust Company, in each case, at Molecular Diagnostics'
expense, promptly following the expiration or termination of the Exchange Offer.

     If I decide to tender common stock, and Molecular Diagnostics accepts the
common stock for exchange, this will constitute a binding agreement between
Molecular Diagnostics and me, subject to the terms and conditions set forth in
the Offering Circular and this Letter of Transmittal.

     Under certain circumstances described in the section of the Offering
Circular entitled "The Exchange Offer -- Conditions to the Exchange Offer,"
Molecular Diagnostics may not be required to accept for exchange any common
stock tendered by this Letter of Transmittal.

     All authority conferred in or agreed to be conferred in this Letter of
Transmittal will survive my death or incapacity, and any obligation of mine
under this Letter of Transmittal will be binding upon my heirs, executors,
administrators, personal representatives, trustees in bankruptcy, legal
representatives, successors and assigns. Except as stated in the Offering
Circular, this tender is irrevocable.

                                        8


                                   SIGN HERE
                         (SEE INSTRUCTIONS 2, 5 AND 6)
      (NOTE: SIGNATURE(S) MUST BE GUARANTEED IF REQUIRED BY INSTRUCTION 2)

     This Letter of Transmittal must be signed by (1) the registered
holder(s) -- which term, for purposes of this Letter of Transmittal, includes
any participant in The Depository Trust Company's system whose name appears on a
security position listing as the holder of the common stock -- exactly as the
name(s) of the registered holder(s) appear(s) on the certificate(s) for the
common stock tendered or on the register of holders maintained by Molecular
Diagnostics, or (2) any person(s) authorized to become the registered holder(s)
by endorsements and documents transmitted with this Letter of
Transmittal -- including any opinions of counsel, certifications and other
information as may be required by Molecular Diagnostics for the common stock to
comply with the restrictions on transfer, if any, applicable to the common
stock. If the signature below is by a trustee, executor, administrator,
guardian, attorney-in-fact, officer of a corporation or another acting in a
similar fiduciary or representative capacity, please set forth the signer's full
title. See Instruction 5.

X
 -------------------------------------------------------------------------------

X
 -------------------------------------------------------------------------------
                SIGNATURE(S) OF EXISTING COMMON STOCK HOLDER(S)

Dated:
- ------------------------------ , 2001

Name(s)
- --------------------------------------------------------------------------------

- --------------------------------------------------------------------------------
                                 (PLEASE PRINT)

Capacity
- --------------------------------------------------------------------------------

Address
- --------------------------------------------------------------------------------
                                                             (ZIP CODE)

Area Code and Telephone No.
- -------------------------------------------------------------------------

                            SIGNATURE(S) GUARANTEED
                        (SEE INSTRUCTION 2, IF REQUIRED)

Eligible Guarantor Institution
- ---------------------------------------------------------------------------

Official Signature
- --------------------------------------------------------------------------------

Dated:
- ------------------------------ , 2001

                                        9


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

<Table>
                                                                                 
                                     PAYER'S NAME: LASALLE BANK NATIONAL ASSOCIATION
- -------------------------------------------------------------------------------------------------------------------------

 SUBSTITUTE                        PART 1 -- PLEASE PROVIDE YOUR TIN IN                ---------------------------------
 FORM W-9                           THE BOX AT RIGHT AND CERTIFY                       Social Security Number
                                    BY SIGNING AND DATING BELOW.
 DEPARTMENT OF THE TREASURY                                                            OR
 INTERNAL REVENUE SERVICE                                                              ---------------------------------
                                                                                       Employer Identification Number
 PAYER'S REQUEST FOR
 TAXPAYER IDENTIFICATION
 NUMBER (TIN)
                                   --------------------------------------------------------------------------------------
                                                                                       PART 3 -- TIN
                                                                                       [ ]  Awaiting
                                   PART 2 --
                                   Certification -- Under penalties of perjury,
                                    I certify that:
                                    (1) The number shown on this form is my correct
                                        Taxpayer Identification Number (or I am
                                        waiting for a number to be issued to me)
                                    (2) I am not subject to backup withholding because
                                        (a) I am exempt from backup withholding, or
                                        (b) I have not been notified by the Internal
                                        Revenue Service (the IRS) that I am subject to
                                        backup withholding as a result of failure to
                                        report all interest or dividends, or (c) the
                                        IRS has notified me that I am no longer
                                        subject to backup withholding and
                                    (3) I am a U.S. person (including U.S. resident
                                        alien).
                                   --------------------------------------------------------------------------------------
                                    CERTIFICATE INSTRUCTIONS -- You must cross out item (2) above if you have been
                                    notified by the IRS that you are currently subject to backup withholding because you
                                    have failed to report all interest and dividends on your tax return. For real estate
                                    transactions, item 2 does not apply. For mortgage interest paid, acquisition or
                                    abandonment of secured property, cancelation of debt, contributions to an individual
                                    retirement arrangement (IRA) and generally, payments other than interest and
                                    dividend, you are not required to sign the Certification, but you must provide your
                                    correct TIN.
                                   SIGNATURE
                                   -----------------------------------------------------------------------------
SIGN HERE                          DATE
                                   ------------------------------------------------------------------------------------
- -------------------------------------------------------------------------------------------------------------------------
</Table>

NOTE: FAILURE TO COMPLETE AND RETURN THIS FORM MAY RESULT IN BACKUP WITHHOLDING
      OF 30.5% OF ANY PAYMENTS MADE TO YOU PURSUANT TO THE OFFER. PLEASE REVIEW
      THE ENCLOSED GUIDELINES FOR CERTIFICATION OF TAXPAYER IDENTIFICATION
      NUMBER ON SUBSTITUTE FORM W-9 FOR ADDITIONAL DETAILS.

       YOU MUST COMPLETE THE FOLLOWING CERTIFICATE IF YOU CHECKED THE BOX
       IN PART 3 OF SUBSTITUTE FORM W-9 INDICATING YOU HAVE APPLIED FOR,
                     AND ARE AWAITING RECEIPT OF YOUR TIN.

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

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

             CERTIFICATE OF AWAITING TAXPAYER IDENTIFICATION NUMBER

<Table>
                                                                
     I certify under penalties of perjury that a taxpayer identification number has not been issued to
me, and either (1) I have mailed or delivered an application to receive a taxpayer identification number
to the appropriate Internal Revenue Service Center or Social Security Administration Office, or (2) I
intend to mail or deliver an application in the near future. I understand that if I do not provide a
taxpayer identification number by the time of payment, 30.5% of all reportable payments made to me will
be withheld.
Signature
- ------------------------------------------------------------
                                                                   Date ------------------------------

Name
- ------------------------------------------------------------
                       (Please Print)
</Table>

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

                                        10


                                  INSTRUCTIONS
         FORMING PART OF THE TERMS AND CONDITIONS OF THE EXCHANGE OFFER

1.  DELIVERY OF LETTER OF TRANSMITTAL AND CERTIFICATES; GUARANTEED DELIVERY
    PROCEDURES.

     You must complete this Letter of Transmittal if you are a holder of common
stock -- which term, for purposes of this Letter of Transmittal, includes any
participant in The Depository Trust Company's system whose name appears on a
security position listing as the holder of the common stock -- and either (1)
you wish to tender the certificates representing your common stock to the
Exchange Agent together with this Letter of Transmittal or (2) you wish to
tender your common stock by book-entry transfer to the Exchange Agent's account
at The Depository Trust Company and you elect to submit this Letter of
Transmittal to the Exchange Agent instead of an Agent's Message. In order to
constitute a valid tender of your common stock, unless you comply with the
procedures for Guaranteed Delivery described below, the Exchange Agent must
receive the following documents at one of the addresses listed above prior to
the expiration of the Exchange Offer: (1) certificates representing the common
stock, in proper form for transfer, or Book-Entry Confirmation of transfer of
the common stock into the Exchange Agent's account at The Depository Trust
Company, (2) a properly completed and duly executed Letter of Transmittal, with
any required signature guarantees, or, in the case of a Book-Entry Confirmation,
an Agent's Message instead of this Letter of Transmittal, and (3) all other
documents required by this Letter of Transmittal.

     If you wish to tender common stock, but (1) the certificates representing
your common stock are not immediately available, (2) time will not permit the
certificates or other required documents to reach the Exchange Agent before the
expiration of the Exchange Offer, or (3) the procedure for book-entry transfer
cannot be completed before the expiration of the Exchange Offer, you may effect
a tender if: (1) the tender is made through an Eligible Guarantor Institution
(as defined below); (2) prior to the expiration of the Exchange Offer, the
Exchange Agent receives from an Eligible Guarantor Institution a properly
completed and duly executed Notice of Guaranteed Delivery, substantially in the
form we have provided, setting forth your name and address and the amount of
common stock you are tendering and stating that the tender is being made by
Notice of Guaranteed Delivery; and (3) the Exchange Agent receives within three
New York Stock Exchange, Inc. ("NYSE") trading days after the date of execution
of the Notice of Guaranteed Delivery: (a) the certificates for all physically
tendered common stock, in proper form for transfer, or a Book-Entry Confirmation
of transfer of the common stock into the Exchange Agent's account at The
Depository Trust Company, as the case may be, (b) a properly completed and duly
executed Letter of Transmittal, with any required signature guarantees, or, in
the case of a Book-Entry Confirmation, an Agent's Message instead of the Letter
of Transmittal, and (c) all other documents required by the Letter of
Transmittal. The Notice of Guaranteed Delivery may be sent by overnight courier,
hand delivery, registered or certified mail or facsimile transmission and must
include a guarantee by an Eligible Guarantor Institution in the form set forth
in the Notice.

     THE METHOD OF DELIVERY OF CERTIFICATES FOR COMMON STOCK, LETTERS OF
TRANSMITTAL, AGENT'S MESSAGES AND ALL OTHER REQUIRED DOCUMENTS IS AT YOUR
ELECTION. IF YOU DELIVER YOUR COMMON STOCK BY MAIL, WE RECOMMEND REGISTERED
MAIL, PROPERLY INSURED, WITH RETURN RECEIPT REQUESTED. IN ALL CASES, YOU SHOULD
ALLOW SUFFICIENT TIME TO ASSURE TIMELY DELIVERY. PLEASE SEND CERTIFICATES FOR
COMMON STOCK, LETTERS OF TRANSMITTAL, AGENT'S MESSAGES OR OTHER REQUIRED
DOCUMENTS TO THE EXCHANGE AGENT AT ONE OF THE ADDRESSES LISTED ABOVE. PLEASE DO
NOT SEND THESE DOCUMENTS TO MOLECULAR DIAGNOSTICS.

     Molecular Diagnostics will not accept any alternative, conditional or
contingent tenders. Each tendering holder, by execution of this Letter of
Transmittal or delivery of an Agent's Message instead of the Letter of
Transmittal, waives any right to receive any notice of the acceptance of such
tender.

                                        11


2.  GUARANTEE OF SIGNATURES.

     No signature guarantee on this Letter of Transmittal is required if:

          (a) this Letter of Transmittal is signed by the registered
     holder -- which term, for purposes of this Letter of Transmittal, includes
     any participant in The Depository Trust Company's system whose name appears
     on a security position listing as the owner of the common stock -- of
     common stock tendered with this Letter of Transmittal, unless such
     holder(s) has completed either the box entitled "Special Issuance
     Instructions" or the box entitled "Special Delivery Instructions" above, or

          (b) the common stock is tendered for the account of a firm that is an
     Eligible Guarantor Institution.

     In all other cases, an Eligible Guarantor Institution must guarantee the
signature(s) on this Letter of Transmittal. See Instruction 5.

     An "Eligible Guarantor Institution" (as defined in Rule 17Ad-15 promulgated
under the Securities Exchange Act of 1934, as amended (the "Exchange Act"))
means:

     - Banks (as defined in Section 3(a) of the Federal Deposit Insurance Act);

     - Brokers, dealers, municipal securities dealers, municipal securities
       brokers, government securities dealers and government securities brokers
       (as defined in the Exchange Act);

     - Credit unions (as defined in Section 19B(1)(A) of the Federal Reserve
       Act);

     - National securities exchanges, registered securities associations and
       clearing agencies (as these terms are defined in the Exchange Act); and

     - Savings associations (as defined in Section 3(b) of the Federal Deposit
       Insurance Act).

3.  INADEQUATE SPACE.

     If the space provided in the box entitled "Description of Common Stock" is
inadequate, the certificate number(s) and/or the amount of common stock and any
other required information should be listed on a separate signed schedule and
attached to this Letter of Transmittal.

4.  PARTIAL TENDERS AND WITHDRAWAL RIGHTS.

     If you are tendering less than all of the common stock evidenced by any
certificate you are submitting, please fill in the common stock which are to be
tendered in column 3 of the box entitled "Description of Common Stock." In that
case, unless you have otherwise indicated by completing the boxes entitled
"Special Issuance Instructions" or "Special Delivery Instructions," new
certificate(s) for the remainder of the common stock that were evidenced by your
old certificate(s) will be sent to the registered holder of the common stock,
promptly after the expiration of the Exchange Offer. All common stock
represented by certificates delivered to the Exchange Agent will be deemed to
have been tendered unless otherwise indicated.


     Except as otherwise provided in this Letter of Transmittal, tenders of
common stock may be withdrawn (i) at any time prior to the expiration of the
Exchange Offer or (ii) after January 28, 2002 if we have not accepted the
tendered common stock for exchange by that date. For a withdrawal pursuant to
clause (i) to be effective, a written notice of withdrawal must be received by
the Exchange Agent prior to the expiration of the Exchange Offer at one of the
addresses listed above. Any notice of withdrawal must specify the name of the
person who tendered the common stock to be withdrawn, identify the common stock
to be withdrawn, including the amount of the common stock, and, where
certificates representing common stock have been transmitted, specify the name
in which the common stock is registered, if different from that of the
withdrawing holder. If certificates representing common stock have been
delivered or otherwise identified to the Exchange Agent, then, prior to the
release of the certificates, the withdrawing holder must also submit the serial
numbers of the particular certificates to be withdrawn and a signed notice of
withdrawal with signatures guaranteed by an Eligible Guarantor Institution
unless the holder is an Eligible Guarantor Institution. If common stock has been
tendered using the procedure for book-entry transfer described in the section of
the


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Offering Circular entitled "The Exchange Offer -- Book-Entry Transfer," any
notice of withdrawal must specify the name and number of the account at The
Depository Trust Company to be credited with the withdrawn common stock and
otherwise comply with the procedures of the book-entry transfer facility. All
questions as to the validity, form and eligibility -- including time of receipt
- -- of these notices will be determined by Molecular Diagnostics. Any such
determination will be final and binding. Any common stock so withdrawn will be
deemed not to have been validly tendered for exchange for purposes of the
Exchange Offer. Any common stock which has been tendered for exchange but which
are not exchanged for any reason will be returned to the registered holder
without cost to that holder promptly after withdrawal, non-acceptance of tender
or termination of the Exchange Offer. In the case of common stock tendered using
the procedure for book-entry transfer described in the section of the Offering
Circular entitled "The Exchange Offer -- Book-Entry Transfer," the common stock
will be credited to the tendering holder's account with The Depository Trust
Company. Properly withdrawn common stock may be retendered at any time prior to
the expiration of the Exchange Offer by following one of the procedures
described in the section of the Offering Circular entitled "The Exchange Offer
- -- Procedures for Tendering Common Stock."


5.  SIGNATURES ON LETTER OF TRANSMITTAL, ASSIGNMENTS AND ENDORSEMENTS.

     If this Letter of Transmittal is signed by the registered holder(s) of the
common stock tendered hereby, the signature(s) must correspond exactly with the
name(s) as written on the face of the certificate(s) without alteration,
enlargement or any change whatsoever.

     If any of the common stock tendered hereby are registered in the name of
two or more joint owners, all such owners must sign this Letter of Transmittal.

     If any tendered common stock is registered in different name(s) on several
certificates, it will be necessary to complete, sign and submit as many separate
Letters of Transmittal as there are different registered holders.

     When this Letter of Transmittal is signed by the registered holder(s) of
the common stock listed and transmitted by this Letter of Transmittal, no
endorsement(s) of certificate(s) or separate stock power is required unless
shares of Series E convertible preferred stock are to be issued in the name of a
person other than the registered holder(s). If Series E convertible preferred
stock is to be issued in the name of a person other than the registered holder
listed, the certificate(s) must be endorsed or accompanied by appropriate stock
power(s) and must be guaranteed by an Eligible Guarantor Institution.

     If a person or persons other than the registered holder(s) of common stock
signs the Letter of Transmittal, certificates representing the common stock must
be endorsed, or accompanied by appropriate stock powers signed exactly as the
name or names of the registered holder(s) that appears on the certificates
representing the common stock and also must be accompanied by any opinions of
counsel, certifications and other information as Molecular Diagnostics may
require in accordance with the restrictions on transfer, if any, applicable to
the common stock. Signatures on certificates or stock powers must be guaranteed
by an Eligible Guarantor Institution.

     If you are a trustee, executor, administrator, guardian, attorney-in-fact,
officer of a corporation, or act in a similar fiduciary or representative
capacity, and wish to sign this Letter of Transmittal or any certificates
representing common stock, you must indicate your status when signing. If you
are acting in any of these capacities, you must submit proper evidence
satisfactory to us of your authority to so act unless we waive this requirement.

6.  SPECIAL ISSUANCE AND DELIVERY INSTRUCTIONS.

     If shares of Series E convertible preferred stock are to be issued in the
name of a person other than the signer of this Letter of Transmittal, or if
shares of Series E convertible preferred stock are to be delivered to someone
other than the signer of this Letter of Transmittal or to an address other than
that shown above, the appropriate boxes on this Letter of Transmittal should be
completed. Certificates representing common stock

                                        13


not exchanged will be returned by mail or, if tendered by book-entry transfer,
by crediting the account indicated above maintained with The Depository Trust
Company. See Instruction 4.

7.  IRREGULARITIES.

     All questions as to the validity, form, eligibility -- including time of
receipt -- and acceptance of common stock tendered for exchange will be
determined by Molecular Diagnostics in its sole discretion. Our determination
will be final and binding. We reserve the absolute right to reject any and all
tenders of common stock improperly tendered or to not accept any common stock,
the acceptance of which might be unlawful as determined by us or our counsel. We
also reserve the absolute right to waive any defects or irregularities or
conditions of the Exchange Offer as to any common stock either before or after
the expiration of the Exchange Offer -- including the right to waive the
ineligibility of any holder who seeks to tender common stock in the Exchange
Offer. Our interpretation of the terms and conditions of the Exchange Offer as
to any particular common stock either before or after the expiration of the
Exchange Offer -- including the terms and conditions of the Letter of
Transmittal and the accompanying instructions -- will be final and binding.
Unless waived, any defects or irregularities in connection with tenders of
common stock for exchange must be cured within a reasonable period of time, as
determined by us. Neither we, the Exchange Agent nor any other person has any
duty to give notification of any defect or irregularity with respect to any
tender of common stock for exchange, nor will we have any liability for failure
to give such notification.

8.  QUESTIONS, REQUESTS FOR ASSISTANCE AND ADDITIONAL COPIES.

     Questions and requests for assistance may be directed to the Exchange Agent
at the addresses and telephone number listed on the front of this Letter of
Transmittal. Additional copies of the Offering Circular, this Letter of
Transmittal or the Notice of Guaranteed Delivery may be obtained from the
Exchange Agent or from your broker, dealer, commercial bank, trust company or
other nominee.

9.  WAIVER OF CONDITIONS.


     Molecular Diagnostic's obligation to complete the Exchange Offer is subject
to the conditions described in the section of the Offering Circular entitled
"The Exchange Offer -- Conditions to the Exchange Offer." These conditions are
for our benefit only and we may assert them regardless of the circumstances
giving rise to any condition. We may also waive any condition other than receipt
of necessary government approvals, in whole or in part, at any time prior to
expiration of the Exchange Offer, in our sole discretion. Our failure at any
time to exercise any of the foregoing rights will not constitute a waiver of
that right and each right is an ongoing right that we may assert at any time.


10.  NO CONDITIONAL TENDERS.

     No alternative, conditional or contingent tenders will be accepted. All
tendering holders of common stock, by execution of this Letter of Transmittal,
waive any right to receive notice of the acceptance of common stock for
exchange.

11.  LOST, DESTROYED OR STOLEN CERTIFICATES.

     If any certificate(s) representing common stock have been lost, destroyed
or stolen, the holder should check the box above regarding lost, destroyed or
stolen certificates and promptly notify the Exchange Agent. The holder will then
be instructed as to the steps that must be taken in order to replace the
certificate(s). This Letter of Transmittal and related documents cannot be
processed until the procedures for replacing lost, destroyed or stolen
certificate(s) have been followed.

12.  TRANSFER TAXES.

     You will not be obligated to pay any transfer taxes in connection with the
tender of common stock in the Exchange Offer unless you instruct us to register
shares of Series E convertible preferred stock in the name of, or request that
common stock not tendered or not accepted in the Exchange Offer be returned to,
a person other than the registered tendering holder. In those cases, you will be
responsible for the payment of any

                                        14


applicable transfer tax. If satisfactory evidence of payment of these taxes or
an exemption from payment is not submitted with this Letter of Transmittal, no
Series E convertible preferred stock will be issued until such evidence is
received by the Exchange Agent.

13.  30.5% BACKUP WITHHOLDING; SUBSTITUTE FORM W-9.

     Under U.S. federal income tax law, a holder's tendered common stock is
accepted for exchange is required to provide the Exchange Agent with the
holder's correct taxpayer identification number ("TIN") on Substitute Form W-9
above. If the Exchange Agent is not provided with the correct TIN, the Internal
Revenue Service may subject the holder or other payee to a $50 penalty. In
addition, cash payments, if any, to such holders or other payees with respect to
common stock exchanged in the Exchange Offer may be subject to 30.5% backup
withholding.

     The box in Part 3 of the Substitute Form W-9 may be checked if the
tendering holder has not been issued a TIN and has applied for a TIN or intends
to apply for a TIN in the near future. If the box in Part 3 is checked, the
holder or other payee must also complete the Certificate of Awaiting Taxpayer
Identification Number above in order to avoid backup withholding.
Notwithstanding that the box in Part 3 is checked and the Certificate of
Awaiting Taxpayer Identification Number is completed, the Exchange Agent will
withhold 30.5% of all payments made prior to the time a properly certified TIN
is provided to the Exchange Agent. The Exchange Agent will retain all amounts
withheld during the 60-day period following the date of the Substitute Form W-9.
If the holder furnishes the Exchange Agent with its TIN within 60 days after the
date of the Substitute Form W-9, the amounts retained during the 60-day period
will be remitted to the holder and no further amounts will be retained or
withheld from payments made to the holder thereafter. If, however, the holder
has not provided the Exchange Agent with its TIN within the 60-day period,
amounts withheld will be remitted to the IRS as backup withholding. In addition,
30.5% of all payments made thereafter will be withheld and remitted to the IRS
until a correct TIN is provided.

     The holder is required to give the Exchange Agent the TIN (e.g., social
security number or employer identification number) of the registered holder of
the common stock or of the last transferee appearing on the transfers attached
to, or endorsed on, the common stock. If the common stock is registered in more
than one name or are not in the name of the actual holder, consult the enclosed
"Guidelines for Certification of Taxpayer Identification Number on Substitute
Form W-9" for additional guidance on which number to report.

     Certain holders -- including, among others, corporations, financial
institutions and certain foreign persons -- may not be subject to these backup
withholding and reporting requirements. These holders should nevertheless
complete the Substitute Form W-9 above, and check the box in Part 2 of the
Substitute Form W-9, to avoid possible erroneous backup withholding. A foreign
person may qualify as an exempt recipient by submitting a properly completed IRS
Form W-8, signed under penalties of perjury, attesting to that holder's exempt
status. Please consult the enclosed "Guidelines for Certification of Taxpayer
Identification Number on Substitute Form W-9" for additional guidance on which
holders are exempt from backup withholding.

     Backup withholding is not an additional U.S. federal income tax. Rather,
the U.S. federal income tax liability of a person subject to backup withholding
will be reduced by the amount of tax withheld. If withholding results in an
overpayment of taxes, a refund may be obtained.

     IMPORTANT: UNLESS YOU COMPLY WITH THE GUARANTEED DELIVERY PROCEDURES
DESCRIBED ABOVE, THIS LETTER OF TRANSMITTAL (OR A FACSIMILE OF THIS LETTER OF
TRANSMITTAL), OR, IN THE CASE OF COMMON STOCK TENDERED BY BOOK-ENTRY TRANSFER TO
THE EXCHANGE AGENT'S ACCOUNT AT THE DEPOSITORY TRUST COMPANY, AN AGENT'S MESSAGE
INSTEAD OF THIS LETTER OF TRANSMITTAL, AND ALL OTHER REQUIRED DOCUMENTS MUST BE
RECEIVED BY THE EXCHANGE AGENT PRIOR TO THE EXPIRATION OF THE EXCHANGE OFFER.

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