<PAGE>   1
                                                                Attachments to
                                                                EXHIBIT 10.14(a)




                                 March 24, 2000



Genomic Solutions, Inc.
4355 Varsity Drive, Suite E
Ann Arbor, MI  48108
                                        AMENDMENT NO. 3 TO LETTER LOAN AGREEMENT
Gentlemen:

         This letter (this "Amendment"), amends the Letter Loan Agreement dated
August 10, 1998 (as amended by the Amendment No. 1 to Letter Loan Agreement
dated April 29, 1999 and Amendment No. 2 to Letter Loan Agreement dated February
29, 2000 but effective as of September 30, 1999, the "Agreement") by and between
Comerica Bank, a Michigan banking corporation ("Bank"), and Genomic Solutions,
Inc., a Delaware corporation ("Company"). Terms used and not otherwise defined
in this Amendment have the meanings ascribed to them in the Agreement.

         In consideration of the mutual promises made in this Amendment, and
other valuable consideration, the receipt and sufficiency of which is
acknowledged, Bank and Company agree as follows:

1.       The first unnumbered paragraph on page one of the Agreement is amended
by replacing the term "Two Million Dollars ($2,000,000)" with the term "Twenty
Two Million Dollars ($22,000,000)."

2  .     Section 1 of the Agreement is amended to insert the following
definitions in appropriate alphabetical order:

         "Cash" shall mean money, currency or a credit balance in a general
         deposit account with a financial institution.


         "Cash Equivalents" shall mean (i) unencumbered securities issued or
         directly and fully guaranteed or insured by the United States of
         America or any agency or instrumentality thereof (provided that the
         full faith and credit of the United States of America is pledged in
         support thereof) having maturities of not more than three years from
         the date of acquisition, (ii) unencumbered marketable direct
         obligations issued by any State of the United States of America or any
         local government or other political subdivision thereof rated (at the
         time of acquisition of such security) at least AA by Standard & Poor's
         Corporation ("S&P") or the equivalent thereof by Moody's Investors
         Service, Inc. ("Moody's") having maturities of not more than one year
         from the date of acquisition, (iii) unencumbered U.S. Dollar

<PAGE>   2


Genomic Solutions, Inc.
March 24, 2000
Page 2


         denominated time deposits, certificates of deposit and bankers'
         acceptances of (x) Bank, (y) any domestic commercial bank of recognized
         standing having capital and surplus in excess of $500,000,000 or (z)
         any bank whose short-term commercial paper rating (at the time of
         acquisition of such security) by S&P is at least A-l or the equivalent
         thereof or by Moody's is at least P-1 or the equivalent thereof (any
         such bank, an "Approved Bank"), in each case with maturities of not
         more than six months from the date of acquisition, (iv) unencumbered
         commercial paper and variable or fixed rate notes issued by Bank or by
         the parent company of Bank and commercial paper and variable rate notes
         issued by, or guaranteed by, any industrial or financial company with a
         short-term commercial paper rating (at the time of acquisition of such
         security) of at least A-1 or the equivalent thereof by S&P or at least
         P-1 or the equivalent thereof by Moody's, or guaranteed by any
         industrial company with a long-term unsecured debt rating (at the time
         of acquisition of such security) of at least AA or the equivalent
         thereof by S&P or the equivalent thereof by Moody's and in each case
         maturing within one year after the date of acquisition and (v)
         unencumbered repurchase agreements with Bank maturing within one year
         from the date of acquisition that are fully collateralized by
         investment instruments that would otherwise be Cash Equivalents.

         "Liquid Assets" shall mean Cash, and Cash Equivalents.

         "unencumbered" shall mean with respect to any asset, that such asset is
         not subject to any voluntary or involuntarily lien, security interest,
         mortgage, pledge or other encumbrance, including without limitation any
         lien or security interest in favor of the Bank.

3.       Section 2 of the Agreement is amended by replacing the term "Two
         Million Dollars ($2,000,000)" with the term "Twenty Two Million Dollars
         ($22,000,000)."

4.       The following Section 2 A is inserted immediately after Section 2:

         2A Standby letters of credit ("Letters of Credit") may be issued by
         Bank on behalf of Company from time to time under the Line of Credit.
         The undrawn amount of the Letters of Credit shall not exceed Two
         Million Dollars ($2,000,000) at any time. Letters of Credit shall be on
         terms and conditions (including fees) and issued subject to
         documentation acceptable to Bank. Each Letter of Credit shall expire on
         the earlier to occur of 360 days from its date of issuance and the
         Maturity Date as set forth in the Note.

5.       Section 3 is amended to add the following Section (g):


<PAGE>   3
Genomic Solutions, Inc.
March 24,  2000
Page 3


         (g) Proceeds of loans under the Line of Credit and Letters of Credit
         shall be used for general, corporate purposes, including working
         capital.

6.       Section 4(m) is amended to replace the term "April 1998 Subordinated
         Debt" with the term "April 1999 Subordinated Debt."

7.       Section 4 of the Agreement is amended to add the following subsections
         (n) and (o):

         (n) Maintain at all times after Company's initial public offering
         (including without limitation after payment of the debt now owing under
         the April 1999 and October, 1999 Subordinated Debt financing)
         unencumbered Liquid Assets of at least $10,000,000.

         (o) Maintain at all times cash collateral acceptable to and under the
         control of the Bank in which Bank shall have a first priority,
         perfected security interest in an amount not less than $20,000,000. If
         and when the Line of Credit is permanently and irrevocably reduced, the
         amount of cash collateral required shall be reduced by the amount by
         which the Line of Credit is reduced.

8.       Section 5(c)(viiI) is amended to read in its entirety:

         (viii) liens or encumbrances on assets of Company and its subsidiaries
         in connection with the April, 1999 Subordinated Debt financing and the
         October, 1999 Subordinated Debt financing.


9.       The form of promissory note annexed to this Amendment as Exhibit A is
         substituted for the form of promissory note annexed to the Agreement as
         Exhibit A.



<PAGE>   4

Genomic Solutions, Inc.
March 24, 2000
Page 4

10. In consideration for the Bank's entering into this Amendment, within 31 days
of the date of this Amendment, the Company shall pay the Bank a non-refundable
closing fee of $37,500. In addition, Company shall reimburse Bank for all of
Bank's out-of-pocket expenses and reasonable attorney fees incurred in
connection with the closing of the transactions contemplated by this Amendment.

11. The Company hereby reaffirms the representations and warranties set forth in
Section 3 of the Agreement and acknowledges and confirms that those
representations and warranties are continuing representations and warranties
during the life of the Agreement.

12. The effectiveness of this Amendment is conditioned on the Bank's receipt of
the following:

          a.   A fully executed promissory note in the form annexed hereto as
               Exhibit A.

          b.   The documents required by the attached Closing Agenda, fully
               executed by the parties thereto the Banks satisfaction.

13. Except as amended by this Amendment, the terms of the Agreement and the
other Loan Documents shall remain in full force and effect.

14. If the foregoing is acceptable to Company, please indicate such with the
authorized signature of Company as provided below.

                                  Very truly yours,

                                  COMERICA BANK



                                  By: Ronald M. Ruks
                                      ------------------------------------------

                                  Its: Assistant Vice President
                                      ------------------------------------------




ACCEPTED AND AGREED:

GENOMIC SOLUTIONS, INC.


<PAGE>   5

Genomic Solutions, Inc.
March 24, 2000
Page 5




By:      Jeffrey S. Williams
         -----------------------
Its:     President and CEO
         -----------------------
Dated:
         -----------------------


Each of the undersigned Guarantors acknowledges the Company's execution of the
foregoing Amendment and consents to the terms of the Amendment. Each Guarantor
ratifies and confirms its Guaranty of the obligations of the Company to the Bank
and acknowledges that such Guaranty remains in fully force and effect in
accordance with its terms.

GENOMIC SOLUTIONS, K.K.



By:      Jeffrey S. Williams
         ---------------------------
Its:     Chairman
         ---------------------------
Dated:
         ---------------------------


GENOMIC SOLUTIONS, LTD.


By:      Jeffrey S. Williams
         ---------------------------
Its:     Chairman
         ---------------------------
Dated:
         ---------------------------



<PAGE>   6


                    AMENDMENT NO.1 TO SUBORDINATION AGREEMENT

         This Amendment No. 1 to Subordination Agreement (this "Amendment") is
made as of March 24, 2000 by and among the Genomic Solutions, Inc., Genomic
Solutions, Ltd. and Genomic Solutions K.K., (each, a "Borrower") and, together,
(the "Borrowers"), the parties listed on the signature pages hereto as Creditors
(each "Creditor") and collectively ("Creditors") and Comerica Bank ("Bank").

                                    RECITALS

A.   The parties have entered into the Subordination Agreement dated as of April
     23, 1999 (the "Subordination Agreement").

B.   The parties wish to amend the Subordination Agreement as provided herein.

     THEREFORE, in consideration of the recitals, and other valuable
consideration, the receipt and sufficiency of which is acknowledge, Bank,
Borrowers and Creditors agree as follows:

1.   The proviso following the phrase (the "Senior Indebtedness") in the tenth
     line of Section 1 of the Subordination Agreement is amended to read:

     provided, however, that Senior Indebtedness does not include aggregate
principal amounts at any one time outstanding in excess of the sum of (a) an
amount equal to $3,000,000 during the calendar year 1999, $6,000,000 during the
calendar year 2000, $7,000,000 during the calendar year 2001 and $8,000,000
during the calendar year 2002 and thereafter, plus (b) the aggregate principal
amount of all indebtedness owing from time to time from the Borrower to the Bank
secured by cash and/or cash equivalents to the extent such indebtedness is paid
or satisfied by such cash and/or cash equivalents.

1.   Section 20 of the Subordination Agreement is amended to add the
following additional subsection 20G.

     G. Notwithstanding anything to the contrary in this Agreement, if the
Borrower closes an initial public offering on or before June 1, 2001 pursuant to
the Registration Statement filed with the Securities and Exchange Commission and
proceeds of that initial public offering exceed $50,000,000 (an "IPO"), then
Creditors may ask for, demand, sue for, take or receive from Borrowers the full
outstanding principal balance of the Notes notwithstanding whether a Standstill
Notice has been given to Creditors.

2.   After an IPO, evidence of the Subordinated Indebtedness shall no longer be
required to contain the restrictive legend set forth in the second sentence of
Section 6 of the Subordination Agreement.



<PAGE>   7




3.    Except as amended by this Amendment, the terms of Subordination Agreement
shall remain in full force and effect.

      Executed as of the date first written above.

                    [Signatures begin on the following page]


<PAGE>   8
   WHITE PINES LIMITED PARTNERSHIP I
   By: White Pines G.P., L.L.C. its general
       partner


   By: /s/ Frederick L. Yocum
       -----------------------------
       Frederick L. Yocum, Chairman



   PACIFIC CAPITAL, L.P.
   By:  WP Pacific G.P., L.L.C., a general
        partner



   By: /s/ Frederick L. Yocum
       -----------------------------
       Frederick L. Yocum, Chairman
IAN R. N. BUND SMITH BARNEY
   PROTOTYPE PS PLAN ACCOUNT
   #206-08291-12445
YOCUM CONSULTING ASSOCIATES, INC.
VOLUNTEER HEALTHCARE ASSOCIATES, L.L.C
MCDONALD INVESTMENTS INC. CUSTODIAN
   FBC S. STERLING MCMILLAN III IRA
   ROLLOVER ACCOUNT #85362191
RONALD G. KALISH LIVING TRUST U/A/D
   SEPTEMBER 9, 1997
LOIS F. MARLER
MCDONALD INVESTMENTS INC. CUSTODIAN
   FBO DANIEL J. BOYLE IRA
   ROLLOVER ACCOUNT #85314893
NATIONAL CITY BANK OF MI/IL CUSTODIAN
   FBO HERBERT S. AMSTER IRA
   ROLLOVER ACCOUNT DATED JUNE 12, 1991
   #MI-1491-00-4
KANTNER AND ASSOCIATES PROFIT SHARING
   PLAN U/A/D JANUARY 1, 1991
MICHAEL G. WILLIAMS
By:  White Pines Management, L.L.C.,
     a Michigan limited liability
     company, attorney-in-fact


By: /s/ Frederick L. Yocum
------------------------------
 Frederick L. Yocum, Chairman


<PAGE>   9



COMERICA BANK                                        BANK'S ADDRESS:


By:  Ronald M. Ruks                                  500 Woodward Avenue
    -------------------------------                  Detroit, MI 48226
Its:  Assistant Vice President
    -------------------------------


                            BORROWER'S ACKNOWLEDGMENT

The undersigned ("Borrowers") accept notice of the subordination created by this
Agreement and agree that they will take no action inconsistent with this
Agreement. Borrowers agree that the Bank may, at its option, without notice and
without limiting Bank's other rights, upon any breach by Creditors holding at
least 10% of the aggregate outstanding principal amount of the Subordinated
Indebtedness ("Material Creditors") of, or purported termination by Material
Creditors of, this Agreement, declare all Senior Indebtedness to be immediately
due and payable and/or terminate any commitments of Bank to Borrowers.


GENOMIC SOLUTIONS, INC.                     BORROWERS' ADDRESS


By:  Jeffrey S. Williams                    4355 Varsity Drive
    -------------------------------         Ann Arbor, MI 48108
Its: President & CEO
    -------------------------------

GENOMIC SOLUTIONS, LTD


By:  Jeffrey S. Williams
    -------------------------------
Its: Chairman
    -------------------------------
GENOMIC SOLUTIONS, K.K.


By:  Jeffrey S. Williams
    -------------------------------
Its: Director
    -------------------------------

<PAGE>   10
                      AMENDMENT NO. 1 TO SUBORDINATION AGREEMENT

     This Amendment No. 1 to Subordination Agreement (this "Amendment") is made
as of March 24, 2000 by and among the Genomic Solutions, Inc., Genomic
Solutions, Ltd. and Genomic Solutions K.K., (each, a "Borrower") and, together,
(the "Borrowers"), the parties listed on the signature pages hereto as Creditors
(each "Creditor") and collectively ("Creditors") and Comerica Bank ("Bank").


                                   RECITALS


A.  The parties have entered into the Subordination Agreement dated as of
    October 28, 1999 (the "Subordination Agreement").

B.  The parties wish to amend the Subordination Agreement as provided herein.

    THEREFORE, in consideration of the recitals, and other valuable
consideration, the receipt and sufficiency of which is acknowledge, Bank,
Borrowers and Creditors agree as follows:

1.  The proviso following the phrase (the "Senior Indebtedness") in the tenth
    line of Section 1 of the Subordination Agreement is amended to read:

    provided, however, that Senior Indebtedness does not include aggregate
principal amounts at any one time outstanding in excess of the sum of (a) an
amount equal to $3,000,000 during the calendar year 1999, $6,000,000 during the
calendar year 2000, $7,000,000 during the calendar year 2001 and $8,000,000
during the calendar year 2002 and thereafter, plus (b) the aggregate principal
amount of all indebtedness owing from time to time from the Borrower to the
Bank secured by cash and/or cash equivalents to the extent such indebtedness is
paid or satisfied by such cash and/or cash equivalents.

1.  Section 20 of the Subordination Agreement is amended to add the following
additional subsection 20G.

    G. Notwithstanding anything to the contrary in this Agreement, if the
Borrower closes an initial public offering on or before June 1, 2001 pursuant
to the Registration Statement filed with the Securities and Exchange Commission
and proceeds of that initial public offering exceed $50,000,000 (an "IPO"),
then Creditors may ask for, demand, sue for, take or receive from Borrowers the
full outstanding principal balance of the Notes notwithstanding whether a
Standstill Notice has been given to Creditors.

2.  After an IPO, evidence of the Subordinated Indebtedness shall no longer be
required to contain the restrictive legend set forth in the second sentence of
Section 6 of the Subordination Agreement.

<PAGE>   11

3.  Except as amended by this Amendment, the terms of Subordination Agreement
shall remain in full force and effect.

    Executed as of the date first written above.


                      [Signatures begin on the following page]
<PAGE>   12


     WHITE PINES LIMITED PARTNERSHIP I
     By:  White Pines G.P., L.L.C. its general
          partner

     By:  /s/ Frederick L. Yocum
          ------------------------------------
          Frederick L. Yocum, Chairman

     PACIFIC CAPITAL, L.P.
     By:  WP Pacific G.P., L.L.C., a general
          partner

     By:  /s/ Frederick L. Yocum
          ------------------------------------
          Frederick L. Yocum, Chairman

IAN R. N. BUND
YOCUM CONSULTING ASSOCIATES, INC.
VOLUNTEER HEALTHCARE ASSOCIATES, L.L.C.
RONALD G. KALISH LIVING TRUST U/A/D
     SEPTEMBER 9, 1997
McDONALD INVESTMENTS INC. CUSTODIAN
     FBO DANIEL J. BOYLE IRA ROLLOVER
     ACCOUNT #85314893
KANTNER AND ASSOCIATES PROFIT SHARING
     PLAN U/A/D JANUARY 1, 1991
MICHAEL G. WILLIAMS
By:  White Pines Management, L.L.C.,
     a Michigan limited liability
     company, attorney-in-fact

By:  /s/ Frederick L. Yocum
     -----------------------------------------
     Frederick L. Yocum, Chairman
<PAGE>   13


COMERICA BANK                            BANK'S ADDRESS:

By: Ronald M. Ruks                       500 Woodward Avenue
   --------------------------            Detroit, MI 48226
Its: Assistant Vice President
    -------------------------

                             BORROWER'S ACKNOWLEDGMENT


The undersigned ("Borrowers") accept notice of the subordination created by
this Agreement and agree that they will take no action inconsistent with this
Agreement.  Borrowers agree that the Bank may, at its option, without notice
and without limiting Bank's other rights, upon any breach by Creditors holding
at least 10% of the aggregate outstanding principal amount of the Subordinated
Indebtedness ("Material Creditors") of, or purported termination by Material
Creditors of, this Agreement, declare all Senior Indebtedness to be immediately
due and payable and/or terminate any commitments of Bank to Borrower:

GENOMIC SOLUTIONS, INC.                      BORROWERS' ADDRESS

By: Jeffrey S. Williams                      4355 Varsity Drive
   -------------------------------           Ann Arbor, MI 48108
Its: President and CEO
    ------------------------------

GENOMIC SOLUTIONS, LTD.

By: Jeffrey S. Williams
   -------------------------------
Its: Chairman
    ------------------------------

GENOMIC SOLUTIONS, K.K.

By: Jeffrey S. Williams
   -------------------------------
Its: Director
    ------------------------------