Exhibit 4.6


                                                  August 20, 2004

Molecular Diagnostics, Inc.
414 North Orleans Street
Suite 502
Chicago, Illinois 60610

Ladies and Gentlemen:

         This Subscription Agreement (the "Agreement") sets forth the agreements
and  understandings   between  the  undersigned   ("Subscriber")  and  Molecular
Diagnostics,  Inc.,  a  corporation  organized  under the laws of Delaware  (the
"Company"),  relating to  Subscriber's  subscription  for,  and purchase of, the
number of  shares  of common  stock,  par  value  $.001 per share  (the  "Common
Stock"), of the Company set forth on the signature page hereto (the "Shares").

         1.  Conditions  to  Subscription  Acceptance  and  Closing.  Subscriber
understands  and  agrees  that  this   subscription   and  the  closing  of  the
transactions  contemplated  hereby  (the  "Closing")  is  made  subject  to  the
following terms and conditions:

                  (a) The  Company  has the  right  to  accept  or  reject  this
subscription  in whole or in part.  Unless this  subscription is rejected by the
Company by October 30, 2004 (which date may be extended to November  15, 2004 by
the Company in its sole discretion without notice to or approval by Subscriber),
this subscription shall be deemed accepted in whole.

                  (b) On or prior to the date of the Closing,  Subscriber  shall
have furnished the Company with such  information,  documents,  certificates and
opinions  as the  Company  may  reasonably  require to  evidence  the  accuracy,
completeness  or  satisfaction of the  representations,  warranties,  covenants,
agreements  and  conditions  herein  contained or as the Company  otherwise  may
reasonably require.

         2.  Subscriber  Representations  and  Warranties.  In  connection  with
Subscriber's   subscription  for,  and  purchase  of,  the  Shares,   Subscriber
represents and warrants to the Company that:

                  (a) If Subscriber  is a natural  person,  Subscriber  (i) is a
bona fide resident of the state or jurisdiction  set forth on the signature page
of this Agreement as Subscriber's home address,  and has no present intention of
becoming  a resident  of any other  state or  jurisdiction;  (ii) is at least 21
years of age; and (iii) is legally  competent to execute this  Agreement and any
other documents and  instruments  required in connection  herewith,  if any (the
"Transaction  Documents").  If Subscriber is an entity,  the person signing this
Agreement  and  the  Transaction  Documents  on  behalf  of the  entity  is duly

<PAGE>

authorized to execute and deliver this Agreement and the  Transaction  Documents
on behalf of Subscriber. This Agreement and the Transaction Documents constitute
the  legal,  valid  and  binding  obligations  of  Subscriber,   enforceable  in
accordance  with their terms,  except as such  enforceability  may be limited by
applicable  bankruptcy,  insolvency  or similar  laws  relating to or  affecting
generally  the  enforcement  of  creditors'  rights  and  remedies  or by  other
equitable principles.

                  (b) The  execution  and  delivery  of this  Agreement  and the
Transaction  Documents by  Subscriber do not, and the  performance  of the terms
hereof and thereof will not,  contravene  any material  law,  rule,  regulation,
order, writ, judgment,  injunction, decree, determination or award applicable to
Subscriber,  or  of  the  charter,  bylaws,  operating  agreement,   partnership
agreement or other governing agreements of Subscriber (if applicable),  and will
not  conflict  with,  or result in any  breach  of,  the  terms,  conditions  or
provisions  of, or constitute a default  under,  or give to others any rights of
termination,  amendment, acceleration or cancellation of, or result in or permit
the creation or imposition of any lien,  charge or  encumbrance  upon any of the
assets of Subscriber  pursuant to any indenture,  mortgage or other agreement or
instrument or any judgment,  decree,  order or decision to which Subscriber is a
party or by which Subscriber is bound.

                  (c) Under existing law, no approval,  authorization,  license,
permit or other action by or filing with any Federal,  state, municipal or other
governmental  commission,  board or agency is required on the part of Subscriber
in connection with the execution and delivery by Subscriber of this Agreement or
the Transaction Documents, or the consummation of the transactions  contemplated
hereby or thereby.

                  (d)  There  are no  actions,  suits or  proceedings  existing,
pending or, to the  knowledge  of  Subscriber,  threatened  against or affecting
Subscriber before any court,  arbitrator or governmental or administrative  body
or agency that would affect the validity or  enforceability of this Agreement or
the Transaction  Documents,  or that would have a material adverse affect on the
ability  of  Subscriber  to  perform  Subscriber's   obligations  hereunder  and
thereunder.

                  (e)  Subscriber has such knowledge and experience in financial
and business  matters so as to be capable of evaluating and  understanding,  and
has  evaluated  and  understood,  the merits and risks of an  investment  in the
Company  and the  purchase  of the  Shares,  and  Subscriber  has been given the
opportunity (i) to obtain  information and to examine all documents  relating to
the Company and the Company's business, (ii) to ask questions of, and to receive
answers from, the Company concerning the Company, the Company's business and the
terms and  conditions  of this  investment,  and (iii) to obtain any  additional
information,  to the extent the  Company  possesses  such  information  or could
acquire such information without  unreasonable  effort or expense,  necessary to
verify the accuracy of any information previously furnished.  All such questions
have been answered to Subscriber's  full  satisfaction,  and all information and
documents,  records and books pertaining to this investment which Subscriber has
requested have been made available to Subscriber.

                  (f) Subscriber is able to bear the substantial  economic risks
of  Subscriber's  investment  in the Company  and the  purchase of the Shares in
that,  among  other  factors,  Subscriber  can  afford to hold the Shares for an


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<PAGE>

indefinite  period and can afford a complete loss of Subscriber's  investment in
the Company.

                  (g) No  material  adverse  change  in  Subscriber's  financial
condition  has taken place  during the past twelve (12) months,  and  Subscriber
will have  sufficient  liquidity with respect to  Subscriber's  net worth for an
adequate period of time to provide for Subscriber's needs and contingencies.

                  (h) Subscriber is relying solely on Subscriber's  own decision
and/or the advice of  Subscriber's  own adviser(s) with respect to an investment
in the Company and the  purchase of the  Shares,  and has neither  received  nor
relied on any communication from the Company or its officers or agents regarding
any legal, investment or tax advice relating to an investment in the Company.

                  (i)  Subscriber  has had an opportunity to read and understand
the provisions of this Agreement and the Transaction Documents,  to consult with
Subscriber's  adviser(s) or counsel  regarding the operation and consequences of
those  provisions,  and  has  considered  the  effect  of  those  provisions  on
Subscriber.

                  (j)  Subscriber  recognizes  that an investment in the Company
involves  substantial  risks  in  that,  among  other  factors:  (i)  successful
operation of the Company  depends on factors  beyond the control of the Company,
and the Company has not had  profitable  operations  from its inception to date;
(ii)  investment in the Company is a speculative  investment and involves a high
degree of risk of loss;  (iii) the  Company is engaged in an  industry  which is
highly competitive and subject to substantial risks; (iv) the Company has a very
limited amount of working capital available to it; and (v) the Shares may not be
registered under applicable federal and state securities laws and,  accordingly,
it may not be  possible to  liquidate  an  investment  in the Company in case of
immediate need of funds or any other emergency,  if at all. Subscriber has taken
full  cognizance  of, and  understands,  such risks and has obtained  sufficient
information to evaluate the merits and risks of an investment in the Company and
the purchase of the Shares.

                  (k)  Subscriber  confirms that none of the Company's  officers
nor any of the  Company's  agents have made any  representations  or  warranties
concerning an  investment in the Company,  including,  without  limitation,  any
representations or warranties  concerning  anticipated financial results, or the
likelihood of success of the operations, of the Company.

                  (l)  Subscriber is acquiring the Shares for  Subscriber's  own
account,  for  investment  and not with a view to, or in  connection  with,  any
public offering or distribution of the same and without any present intention to
sell  the  same at any  particular  event  or  circumstance.  Subscriber  has no
agreement or other  arrangement with any person to sell,  transfer or pledge any
part of the  Shares  which  would  guarantee  Subscriber  any  profit or protect
against any loss with respect to the Shares.

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<PAGE>

                  (m) Subscriber  understands  that no U.S.  Federal or state or
international  agency has passed on or made any recommendation or endorsement of
an investment in the Shares.

                  (n)  Subscriber  understands  that  the  Shares  have not been
registered  under  the  Securities  Act of 1933,  as  amended  (the  "Act"),  or
applicable  U.S.  state  securities  laws or any  securities  laws of any  other
jurisdiction,   and  are  being  offered  and  sold  under  an  exemption   from
registration  provided  by such laws and the rules and  regulations  thereunder.
Further,  Subscriber  understands  that the  Company is under no  obligation  to
register  the  Shares  or to comply  with any  exemption  under  any  applicable
securities  laws with  respect  thereto or any other  ownership  interest in the
Company.  Subscriber  may therefore be required to bear the economic risks of an
investment  in the Company for an  indefinite  period of time because the Shares
cannot be resold unless registered under applicable securities laws or unless an
exemption from such registration is available.  Subscriber also understands that
(i) the  exemption  provided  by Rule  144  under  the Act may not be  available
because of the conditions and  limitations of such rule, and that in the absence
of  the  availability  of  such  rule,  any  disposition  by  Subscriber  of any
securities of the Company may require compliance with some other exemption under
the Act; and, (ii) the Company is under no obligation  and does not plan to take
any  action  in  furtherance  of  making  Rule  144 or any  other  exemption  so
available.

                  (o) If Subscriber is required in the future to file a Form 144
with the Securities and Exchange  Commission in connection  with sales of Shares
or any other  ownership  interest in the Company  pursuant to Rule 144 under the
Act, Subscriber will deliver a copy of such form to the Company at the same time
and each time  Subscriber  is  required to file a copy with the  Securities  and
Exchange Commission.

                  (p)  Subscriber  is an  "accredited  investor" as such term is
defined in Rule 501(a)  promulgated  under the Act.  Subscriber will execute and
deliver the Confidential  Accredited Investor  Questionnaire  attached hereto as
Exhibit A simultaneously with the execution and delivery of this Agreement.

                  (q) Subscriber agrees that the foregoing  representations  and
warranties  will  survive the sale of the Shares to  Subscriber,  as well as any
investigation made by any party relying on same.

                  (r) Except as  Subscriber  shall have  clearly  and  expressly
disclosed to the Company, Subscriber has not authorized any underwriter, broker,
dealer,  agent or finder to act on Subscriber's behalf (nor does Subscriber have
any  knowledge  of any  broker,  dealer,  agent or finder  purporting  to act on
Subscriber's  behalf)  with respect to  Subscriber's  purchase of the Shares and
Subscriber  has not paid  directly  or  indirectly  any  commission  or  similar
remuneration  with  respect to such  acquisition.  Subscriber  hereby  agrees to
indemnify and hold harmless the Company and its  directors,  officers and agents
from and against any cost, expense, claim, liability or damage arising out of or
resulting from a breach of such representation and warranty.

         3.       General Provisions.

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<PAGE>

                  (a)  This  Agreement  will be  governed  by and  construed  in
accordance with the substantive  laws of the State of Delaware without regard to
rules thereof relating to conflicts of laws.

                  (b) This  Agreement  and the  Transaction  Documents  together
constitute the entire agreement  between the parties with respect to the subject
matter  hereof and thereof and supersede  any prior  subscription  agreement for
Shares  executed by Subscriber.  This Agreement may be amended only by a writing
executed by the parties.

                  (c)  The  Shares  will  be  assigned  or  transferred  only in
accordance  with  applicable  law  and  the  terms  of  this  Agreement  and the
Transaction Documents.

                  (d)  This  Agreement  will  survive   Subscriber's   death  or
dissolution and will be binding upon Subscriber's successors,  heirs, assignees,
representatives and distributees.

                        (Signatures appear on next page.)

                                  * * * * * *


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<PAGE>

         IN WITNESS WHEREOF, Subscriber has hereby executed this Agreement as of
the date set forth above.

SUBSCRIBER:

If an Individual:                           If an Entity:

                                            Name of Entity:
                                                           ---------------------

__________________________                  By:
                                               ---------------------------------
[Name]                                         Name:
                                               Title:

Mailing Address:

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

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

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


E-Mail Address:
                  --------------------------------------------

Social Security Number/U.S. Employer Identification Number:
                                                              ------------------

Number of Shares for which Subscription is tendered:

Purchase Price:
                 ---------------------------

Aggregate Consideration:
                          ------------------------------------



ACCEPTED:

Molecular Diagnostics, Inc.,
   a Delaware corporation



By: _________________________________
    Name:
    Title:

Date of Acceptance:
                   -------------------------


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<PAGE>

                                    EXHIBIT A

                 Confidential Accredited Investor Questionnaire

         The undersigned represents and warrants that he, she or it comes within
one of the categories marked below, and that for any category marked, he, she or
it has  truthfully set forth the factual basis or reason the  undersigned  comes
within that category.  ALL INFORMATION IN RESPONSE TO THIS QUESTIONNAIRE WILL BE
KEPT STRICTLY  CONFIDENTIAL.  The undersigned  agrees to furnish such additional
information as is reasonably  necessary in order to verify the answers set forth
below.

Please mark next to each applicable paragraph:

         _____    a.  The  undersigned  is an  individual  (not  a  partnership,
                  corporation,  etc.) whose  individual net worth,  or joint net
                  worth with his or her spouse, presently exceeds $1,000,000.

                           Explanation.   In  calculating  net  worth,  you  may
                           include equity in personal  property and real estate,
                           including your principal residence,  cash, short-term
                           investments, stock and securities. Equity in personal
                           property  and  real  estate  should  be  based on the
                           appraised  fair market value of such  property,  less
                           debt secured by such property.

         _____    b.  The  undersigned  is an  individual  (not  a  partnership,
                  corporation,  etc.) who had an income in excess of $200,000 in
                  each of the two most recent years, or joint income with his or
                  her spouse in excess of  $300,000  in each of those  years (in
                  each case including foreign income,  tax exempt income and the
                  full amount of capital  gains and losses,  but  excluding  any
                  income of other  family  members  and any  unrealized  capital
                  appreciation),  and has a reasonable  expectation  of reaching
                  the same income level in the current year.

         _____    c.  The  undersigned  is  a  director  or executive officer of
                  Molecular Diagnostics, Inc. or a subsidiary thereof.

         _____    d.  The  undersigned  is  (i) a bank  or a  savings  and  loan
                  association,   (ii)  a  registered  broker  dealer,  (iii)  an
                  insurance  company,  (iv) a registered  investment  company or
                  business  development  company,  (v) a licensed small business
                  investment company,  (vi) a plan established and maintained by
                  a  state,  its  political  subdivisions,   or  any  agency  or
                  instrumentality  of a state or its political  subdivisions (or
                  any agency or instrumentality thereof), for the benefit of its
                  employees,  if  such  plan  has  total  assets  in  excess  of
                  $5,000,000,  (vii) an employee benefit plan within the meaning
                  of Title I of ERISA,  if the investment  decision is made by a
                  plan  fiduciary  which  is  either  a bank,  savings  and loan
                  association,   insurance  company  or  registered   investment
                  adviser  or  if  the  plan  has  total  assets  in  excess  of

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<PAGE>

                  $5,000,000  or  is  a   self-directed   plan  with  investment
                  decisions   made  solely  by  persons   that  are   accredited
                  investors.

                  Describe entity.  ____________________________________________

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

         _____    e.   The undersigned is a private business development company
                  as  defined in  Section  202(a)(22) of the Investment Advisers
                  Act of 1940, as amended.

                  Describe entity. _____________________________________________

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

         _____    f. The  undersigned  is a corporation,  partnership,  business
                  trust or non-profit organization within the meaning of Section
                  501(c)(3) of the Internal  Revenue Code,  as amended,  in each
                  case not formed for the specific purpose of potentially making
                  an investment in connection  herewith and with total assets in
                  excess of $5,000,000.

                  Describe entity. _____________________________________________

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

         _____    g. The  undersigned  is a trust (not  formed for the  specific
                  purpose of  potentially  making an  investment  in  connection
                  herewith) with total assets in excess of $5,000,000, where the
                  purchase  is  directed  by a  person  with the  knowledge  and
                  experience  in  financial  and  business  matters  to  capably
                  evaluate the merits and risks of the  prospective  investment,
                  as set  forth  in Rule  506(b)(2)(ii)  promulgated  under  the
                  Securities Act of 1933, as amended.

         _____    h. The undersigned is an entity all the equity owners of which
                  are  "accredited  investors"  within  one or more of the above
                  categories.

                  Describe entity. _____________________________________________

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


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<PAGE>

         The  undersigned  is  aware  of  the   significance  of  the  foregoing
representations.  The  undersigned is also aware that the above  representations
made by him,  her or it will be relied upon in  connection  with any  investment
made in Molecular  Diagnostics,  Inc.  pursuant to the accompanying  document or
documents.



Date:
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                                        Signature


                                        ----------------------------------------
                                        Print name


                                        Address:
                                                  ------------------------------

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