<PAGE>
                                                                 EXHIBIT 10.1(b)



                               SECOND AMENDMENT TO
                   SALES, MARKETING AND DISTRIBUTION AGREEMENT


         THIS SECOND AMENDMENT TO SALES, MARKETING AND DISTRIBUTION AGREEMENT
(the "Second Amendment") is made and entered into as of January 1, 2002 (the
"Effective Date"), by and between GENOMIC SOLUTIONS INC., a Delaware corporation
("GSI") and PERKINELMER LIFE SCIENCES, INC., a Delaware corporation and its
Affiliates ("PKI"). "Affiliates" of PKI shall mean any person, corporation or
other business entity controlled, controlled by or under common control with
PKI, with "control" meaning a fifty percent (50%) or greater ownership interest.

The following facts underlie this Agreement:

         Pursuant to a certain Sales, Marketing and Distribution Agreement dated
         December 14, 1999 (the "Original Agreement"), as amended by a First
         Amendment to Sales, Marketing and Distribution Agreement dated April
         18, 2001 (the "First Amendment"), Genomic Solutions Inc. appointed
         PerkinElmer, Inc. as its representative to promote, market and
         distribute its products. The parties desire to further amend the
         Original Agreement and the First Amendment, pursuant to the terms and
         conditions of this Second Amendment.

         NOW THEREFORE, for and in consideration of the mutual covenants and
undertakings set forth herein, the parties hereby further amend the Original
Agreement and the First Amendment as follows:

1.       DEFINITIONS. All capitalized terms defined in the Original Agreement,
         as amended by the First Amendment, shall have the meanings set forth in
         such agreements. In addition, the Original Agreement and First
         Amendment are further amended to add the following new defined term:

                  "INVESTIGATOR PRODUCTS" means GSI's Investigator(TM) 2D gel
                  hardware (consisting of gel rigs, casting rigs, power supplies
                  and chillers) and related consumables, including Duracryl(R).

2.       GSI DISTRIBUTOR APPOINTMENTS. Exhibit A of the First Amendment is
         superceded and replaced in its entirety by Exhibit A, attached hereto.
         Exhibit B-1 of the First Amendment is deleted in its entirety. In
         addition, Section 3(a) -- 3(d) of the Original Agreement and Sections
         3(b) and 3(c) of the First Amendment are superceded and replaced in
         their entirety as follows:

         (a)      Non-Exclusive Rights and Responsibilities of PKI. Effective as
                  of the date of this Agreement, PKI shall have the
                  non-exclusive right and responsibility to engage in sales,
                  marketing, distribution and field service activities:

                  (i)      with respect to GSI Products (other than those
                           covered by (ii) and (iii) below), in any market or
                           geographical area other than Core Markets, provided,
                           that PKI shall have the right to distribute products
                           of GSI's Cartesian Technologies subsidiary outside of
                           Core Markets as provided in Exhibit B attached;

<PAGE>

                  (ii)     with respect to GeneMAP DNA Microarrays, Investigator
                           Products, and the HybStation currently marketed by
                           GSI in any market or geographical area of the world;
                           and

                  (iii)    with respect to the G3Library Management System
                           currently marketed by GSI, in any market or
                           geographical area of the world other than Japan.

3.       ADDITIONAL AMENDMENTS

         (a)      The first sentence of Section 5(e) of the First Amendment is
                  amended to delete the words "and Proteomic Services".

         (b)      Section 6(a) of the First Amendment is amended and superceded
                  in its entirety to read as follows:

                           PKI shall have the non-exclusive right and
                           responsibility to engage in sales, marketing,
                           distribution and field service activities with
                           respect to GeneMAP DNA Microarrays throughout the
                           world. PKI shall be permitted to purchase GeneMAP DNA
                           Microarrays in bulk, with minimum purchases of ten
                           arrays for each array type, and to repackage or sell
                           such bulk purchased arrays on a private label basis
                           under such name as PKI shall elect, provided, that
                           PKI shall be responsible for providing all support
                           for such repackaged or private labeled arrays.

         (c)      Section 6(b) of the Original Agreement and Section 7 of the
                  First Amendment are deleted in their entirety.

         (d)      Section 8(b) of the First Amendment is amended to delete the
                  fourth and fifth sentences and to add the following:

                           All orders shall be bona fide, non-cancelable and
                           properly addressed, except that PKI reserves the
                           right to cancel in writing any purchase order not
                           shipped by GSI within 60 days of order receipt. GSI
                           may ship product upon receipt of any order to the
                           designated address, provided, that up to 10% of PKI's
                           purchase orders may specify a ship date within the
                           same fiscal quarter as the purchase order date and
                           GSI shall ship the product on such designated ship
                           date.

4.       EFFECT OF AMENDMENT. Except as provided in this Second Amendment, all
         other terms of the Original Agreement and First Amendment shall remain
         in full force and effect without modification.



                         [signatures on following page]



                                       2

<PAGE>

         IN WITNESS WHEREOF, the undersigned have executed and delivered this
Second Amendment to Sales, Marketing and Distribution Agreement as of the date
and year first above written.

                               GENOMIC SOLUTIONS INC.

                               By:      /s/ Jeffrey S. Williams
                                        --------------------------------------

                               Its:     President and Chief Executive Officer

                               PERKINELMER LIFE SCIENCES, INC.

                               By:      Petri Myllyneva
                                        --------------------------------------

                               Its:     Senior Vice President
                                        --------------------------------------


















                                       3

<PAGE>
                                    EXHIBIT A


<TABLE>
<CAPTION>
-----------------------------------------------------------------
                                                     2002 PRICES
GSNL PRODUCT                                         PKI TRANSFER
-----------------------------------------------------------------
<S>                                                  <C>
 G3 Picking                                           $      ***
 G3 32 pin                                            $      ***
 G3 48 Pin                                            $      ***
 G3 Librarian                                         $      ***
 Hybridization Station                                $      ***
 UC-4                                                 $      ***
 GeneTAC LS-IV  2c                                    $      ***
 GeneTAC LS-IV 4c                                     $      ***
 Integtrator s/w                                      $      ***
 4-day Biochip Training Course                        $      ***
 2-day Biochip Training Course

   Investigator 2-D                                   $      ***
   ProPic*                                            $      ***
   ProGest                                            $      ***
   ProMS                                              $      ***
   ProPrep - four plate                               $      ***
   Protein Warehouse                                  $      ***
 3-day Proteomics Training Course                     $      ***
 1-day Proteomics Training Course                     $      ***
</TABLE>

Genemap Microarrays: ***% discount off U.S. list price

All other reagents and consumables: ***% discount off list price

All other GSI products not detailed above (e.g., upgrade kits, etc.) shall
remain at the current 2001 prices.


***Certain information on this page has been omitted and filed separately with
the Commission. Confidential treatment has been requested for the omitted
portion.






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<PAGE>
                                    EXHIBIT B



The following is a list of countries where Genomic Solutions subsidiary,
Cartesian Technologies, Inc., has current exclusive distribution relationships.
Any extension or renewal of such relationships will be subject to PerkinElmer's
right to engage in distribution of Cartesian products in such countries on a
non-exclusive basis. In addition, in the event that Genomic Solutions terminates
any distributors in such countries prior to expiration of existing agreements
for non-performance, PerkinElmer shall be permitted to distribute Cartesian
products in such countries on a non-exclusive basis.

DISTRIBUTOR COUNTRY                                  TERMINATION DATE
-------------------                                  ----------------

Singapore                                            9/29/02

Malaysia                                             9/29/02

Thailand                                             10/10/02

China                                                12/31/03*

Taiwan                                               12/31/03*

Korea                                                12/31/03*

Denmark                                              12/31/02

Sweden                                               12/31/02

Finland                                              12/31/02

Norway                                               12/31/02

Netherlands                                          12/31/02

Belgium                                              12/31/02

Germany                                              12/31/02

*Termination dates agreed to based on recent negotiations with documentation in
process



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