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                                                                EXHIBIT 10.14(d)


                                   EXHIBIT A

              [COMERICA LOGO]MASTER REVOLVING NOTE
            Variable Rate-Maturity Date-Optional Advances (Business and
Commercial Loans Only)

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<S>                     <C>                       <C>                     <C>
========================================================================================================
AMOUNT                   NOTE DATE                 MATURITY DATE           TAX IDENTIFICATION NUMBER
$32,000,000              April       , 2000        July 1, 2001                        38-3383038
                               ------
----------------------------------------------------------------------------------------------------
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ON THE MATURITY DATE, as stated above, for value received, the undersigned
promise(s) to pay to the order of Comerica Bank ("Bank"), at any office of the
Bank in the State of Michigan, Thirty Two Million Dollars (U.S.) (or that
portion of it advanced by the Bank and not repaid as later provided) with
interest until maturity, whether by acceleration or otherwise, or until Default,
as later defined, at a per annum rate equal to the Bank's prime rate from time
to time in effect minus one percent (1%) per annum so long as the aggregate
principal balance of this Note is greater than $2,000,000 and at a per annum
rate equal to the Bank's prime rate from time to time in effect so long as the
aggregate principal balance outstanding under this Note is $2,000,000 or less,
and after that at a rate equal to the rate of interest otherwise prevailing
under this Note plus three percent (3%) per annum (but in no event in excess of
the maximum rate permitted by law). The Bank's "prime rate" is that annual rate
of interest so designated by the Bank and which is changed by the Bank from time
to time. Interest rate changes will be effective for interest computation
purposes as and when the Bank's prime rate changes. Interest shall be calculated
on the basis of a 360-day year for actual number of days the principal is
outstanding. Accrued interest on this Note shall be payable on the first day of
each month commencing May 1, 2000, until the Maturity Date (set forth above)
when all amounts outstanding under this Note shall be due and payable in full.
If the frequency of interest payments is not otherwise specified, accrued
interest on this Note shall be payable monthly on the first day of each month.
If any payment of principal or interest under this Note shall be payable on a
day other than a day on which the Bank is open for business, this payment shall
be extended to the next succeeding business day and interest shall be payable at
the rate specified in this Note during this extension. A late payment charge
equal to five percent (5%) of each late payment may be charged on any payment
not received by the Bank within ten (10) calendar days after the payment due
date, but acceptance of payment of this charge shall not waive any Default under
this Note.

The principal amount payable under this Note shall be the sum of all advances
made by the Bank to or at the request of the undersigned, less principal
payments actually received in cash by the Bank. The books and records of the
Bank shall be the best evidence of the principal amount and the unpaid interest
amount owing at any time under this Note and shall be conclusive absent manifest
error. No interest shall accrue under this Note until the date of the first
advance made by the Bank; after that interest on all advances shall accrue and
be computed on the principal balance outstanding from time to time under this
Note until the same is paid in full.

This Note and any other indebtedness and liabilities of any kind of the
undersigned (or any of them) to the Bank, and any and all modifications,
renewals or extensions of it, whether joint or several, contingent or absolute,
now existing or later arising, and however evidenced (collectively
"Indebtedness"), are secured by and the Bank is granted a security interest in
all items deposited in any account of any of the undersigned with the Bank and
by all proceeds of these items (cash or otherwise), all account balances of any
of the undersigned from time to time with the Bank, by all property of any of
the undersigned from time to time in the possession of the Bank and by any other
collateral, rights and properties described in each and every deed of trust,
mortgage, security agreement, pledge, assignment and other security or
collateral agreement which has been, or will at any time(s) later be, executed
by any (or all) of the undersigned to or for the benefit of the Bank
(collectively "Collateral"). Notwithstanding the above, (i) to the extent that
any portion of the Indebtedness is a consumer loan, that portion shall not be
secured by any deed of trust, mortgage on or other security interest in any of
the undersigned's principal dwelling or in any of the undersigned's real
property which is not a purchase money security interest as to that portion,
unless expressly provided to the contrary in another place, or (ii) if the
undersigned (or any of them) has(have) given or give(s) Bank a deed of trust or
mortgage covering California real property, that deed of trust or mortgage shall
not secure this


<PAGE>   2



Note or any other indebtedness of the undersigned (or any of them), unless
expressly provided to the contrary in another place.

Upon the occurrence and at any time during the continuance of any "Event of
Default" under that certain Letter Agreement dated as of August 10, 1998, by and
between the undersigned and Bank, as the same may be amended from time to time,
Bank may, at its option and without prior notice to the undersigned, declare any
or all of the Indebtedness (whether under this Note or otherwise) to be
immediately due and payable (notwithstanding any provisions contained in the
evidence of it to the contrary), sell or liquidate all or any portion of the
Collateral, set off against the Indebtedness any amounts owing by the Bank to
the undersigned, charge interest at the default rate provided in the document
evidencing the relevant Indebtedness, and exercise any one or more of the rights
and remedies granted to the Bank by any agreement with the undersigned
(including, without limitation, said Letter Agreement) or given to it under
applicable law. All payments under this Note shall be in immediately available
United States funds, without setoff or counterclaim.

If this Note is signed by two or more parties (whether by all as makers or by
one or more as an accommodation party or otherwise), the obligations and
undertakings under this Note shall be that of all and any two or more jointly
and also of each severally. This Note shall bind the undersigned, and the
undersigned's respective heirs, personal representatives, successors and
assigns. The undersigned waive(s) presentment, demand, protest, notice of
dishonor, notice of demand or intent to demand, notice of acceleration or intent
to accelerate, and all other notices and agree(s) that no extension or
indulgence to the undersigned (or any of them) or release, substitution or
nonenforcement of any security, or release or substitution of any of the
undersigned, any guarantor or any other party, whether with or without notice,
shall affect the obligations of any of the undersigned. The undersigned waive(s)
all defenses or right to discharge available under Section 3-605 of the Michigan
Uniform Commercial Code and waive(s) all other suretyship defenses or right to
discharge. The undersigned agree(s) that the Bank has the right to sell, assign,
or grant participations or any interest in, any or all of the Indebtedness, and
that, in connection with this right, but without limiting its ability to make
other disclosures to the full extent allowable, the Bank may disclose all
documents and information which the Bank now or later has relating to the
undersigned or the Indebtedness. The undersigned agree(s) that the Bank may
provide information relating to this Note or relating to the undersigned to the
Bank's parent, affiliates, subsidiaries and service providers.

The undersigned agree(s) to reimburse the holder or owner of this Note upon
demand for any and all costs and expenses (including without limit, court costs,
legal expenses and reasonable attorney fees, whether inside or outside counsel
is used, whether or not suit is instituted and, if suit is instituted, whether
at the trial court level, appellate level, in a bankruptcy, probate or
administrative proceeding or otherwise) incurred in collecting or attempting to
collect this Note or incurred in any other matter or proceeding relating to this
Note.

The undersigned acknowledge(s) and agree(s) that there are no contrary
agreements, oral or written, establishing a term of this Note and agree(s) that
the terms and conditions of this Note may not be amended, waived or modified
except in a writing signed by an officer of the Bank expressly stating that the
writing constitutes an amendment, waiver or modification of the terms of this
Note. As used in this Note, the word "undersigned" means, individually and
collectively, each maker, accommodation party, indorser and other party signing
this Note in a similar capacity. If any provision of this Note is unenforceable
in whole or part for any reason, the remaining provisions shall continue to be
effective. THIS NOTE IS MADE IN THE STATE OF MICHIGAN AND SHALL BE GOVERNED BY
AND CONSTRUED IN ACCORDANCE WITH THE INTERNAL LAWS OF THE STATE OF MICHIGAN,
WITHOUT REGARD TO CONFLICT OF LAWS PRINCIPLE.

THE MAXIMUM INTEREST RATE SHALL NOT EXCEED 25% PER ANNUM, OR THE HIGHEST
APPLICABLE USURY CEILING, WHICHEVER IS LESS.

This Note replaces by renewal the undersigned's Master Revolving Note dated
March 24, 2000 in favor of the Bank in the principal amount of $22,000,000.


<PAGE>   3



THE UNDERSIGNED AND THE BANK ACKNOWLEDGE THAT THE RIGHT TO TRIAL BY JURY IS A
CONSTITUTIONAL ONE, BUT THAT IT MAY BE WAIVED. EACH PARTY, AFTER CONSULTING (OR
HAVING HAD THE OPPORTUNITY TO CONSULT) WITH COUNSEL OF THEIR CHOICE, KNOWINGLY
AND VOLUNTARILY, AND FOR THEIR MUTUAL BENEFIT, WAIVES ANY RIGHT TO TRIAL BY JURY
IN THE EVENT OF LITIGATION REGARDING THE PERFORMANCE OR ENFORCEMENT OF, OR IN
ANY WAY RELATED TO, THIS NOTE OR THE INDEBTEDNESS.

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<CAPTION>
<S><C>

       GENOMIC SOLUTIONS INC.                                 By: Jeffrey S. Williams       Its: President & CEO
----------------------------------------------------------       -------------------------      -------------------------------
        obligor name typed/printed                                    signature of          title (if applicable)

                                                              By: Steven J. Richralsky      Its: Executive Vice President & CFO
                                                                 -------------------------      -------------------------------
                                                                      signature of          title (if applicable)

                                                              By:                           Its:
                                                                 -------------------------      -------------------------------
                                                                      signature of          title (if applicable)

                                                              By:                           Its:
                                                                 -------------------------      -------------------------------
                                                                      signature of          title (if applicable)


4355 Varsity Drive, Suite E                           Ann Arbor               Michigan                      48108
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street address                                          city                      state             zip code


-------------------------------------------------------------------------------------------- ----------------------------------
                                     FOR BANK USE ONLY                                       ccar #
----------------------------- --------------------- ---------------------------------------------------------------------------
loan officer initials         loan group name       obligor name

----------------------------- --------------------- ------------------------- --------------------------- ---------------------
loan officer id. no.          loan group no.        obligor no.               note no.                    amount

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

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