Exhibit 10.91a  Certain
              confidential information contained in this document, marked by brackets
              and the word "REDACTED" ([REDACTED]) ,
              has
              been omitted and filed separately with the Securities and Exchange
              Commission
              pursuant to Rule 24b-2 of the Securities Exchange Act of 1934, as
              Amended.
 
 
 **Amendment
              No. 1 to**
 **Xenogen
              License Agreement For Real-Time In Vivo Imaging Technology**
 
 This
              First Amendment to the Xenogen License Agreement For Real-Time In Vivo
              Imaging
              Technology, effective November 20, 2004 (the " Agreement ”),
              by
              and between Xenogen
              Corporation, with offices at 860 Atlantic Avenue, Alameda, California
              94501
              (“Xenogen”) and Gene
              Logic, Inc., a corporation with a principal place of business at 610
              Professional Drive, Gaithersburg, Maryland 20879 (“GL”) is effective as of the
              19th day of November, 2005 (the "First Amendment Effective Date").
  **W
              I T N E S S E T H:**
 
 The
              Parties desire
              to
              amend the Agreement in certain respects upon the terms and conditions
              set forth
              below. I n
              consideration of the foregoing premises and the mutual covenants set
              forth
              below, the Parties do hereby amend the Agreement and otherwise agree
              as
              follows:
 
 1.  Effect :
              Provided that both Parties execute this First Amendment not later than
              November
              23, 2005, this First Amendment shall be effective for all purposes
              as of the
              First Amendment Effective Date, and except as otherwise expressly modified
              by
              this First Amendment, the Agreement shall remain in full force and
              effect in
              accordance with its terms. All terms and capitalized words used in
              this First
              Amendment not otherwise defined herein shall have the same meaning
              for such
              terms as set forth in the Agreement.
 
 2.  Additional
              System Purchase :
              Pursuant to Sections 2.1(b) and 3.5(a) of the Agreement, GL hereby
              purchases an
              Additional System from Xenogen for a purchase price of [REDACTED] dollars
              ($[REDACTED]) plus shipping and insurance charges. Xenogen will deliver
              and
              install the Additional System prior to December 31, 2005.
 
 3.  Amendment
              to Section 3.3 - Bioware :
              Section
              3.3 of the Agreement is hereby amended by replacing subsection (c)
              as
              follows:
 
 "(c)  Consideration. During
              the Term, Bioware cell lines and bacterial strains will be priced at
              a
              non-refundable initial fee of [REDACTED] dollars
              ($ [REDACTED] )
              per
              cell line or strain, with a non-refundable annual renewal fee of [REDACTED] dollars
              ($ [REDACTED] )
              per
              cell line or strain. Xenogen will invoice Licensee for Bioware requested
              by Licensee upon
              shipment and annually thereafter .
              After
              Licensee has made the foregoing annual payments for Bioware for [REDACTED]
              years, Licensee will have a fully paid-up, non-exclusive, non-transferable
              license to such LPTA Model line. “
  
 4.  Amendment
              to Section 3.4 - LPTA ® Animal Models :
              Section
              3.4 of the Agreement is hereby amended by replacing
 
 “ During
              the Term, LPTA Models will be priced at a non-refundable fee of [REDACTED] dollars
              ($ [REDACTED] )
              per
              animal (minimum quantity of twenty animals), or, for breeding pairs,
              a
              non-refundable initial fee of [REDACTED] dollars
              ($ [REDACTED] )
              per
              line, with a non-refundable annual renewal fee of [REDACTED] dollars
              ($ [REDACTED] )
              per
              line. As long as Licensee maintains its access rights to at least one
              such line
              during the Term, then breeding pairs for subsequent lines will be priced
              at a
              non-refundable initial fee of [REDACTED] dollars
              ($ [REDACTED] )
              per
              line, with a non-refundable annual renewal fee of [REDACTED] dollars
              ($ [REDACTED] )
              per
              line”
 with
 “During
              the Term, LPTA Models will be priced at a non-refundable fee of [REDACTED] dollars
              ($ [REDACTED] )
              per
              animal (minimum quantity of twenty animals), or breeding pairs will
              be priced at
              a non-refundable initial fee of [REDACTED] dollars
              ($ [REDACTED] )
              per
              line, with a non-refundable annual renewal fee of [REDACTED] dollars
              ($ [REDACTED] )
              per
              line. After Licensee has made the foregoing annual payments for an
              LPTA Model
              line for [REDACTED] years, Licensee will have a fully paid-up, non-exclusive,
              non-transferable license to such LPTA Model line. “
 
 5.  Amendment
              to Section 3.5 - Payments :
              Section
              3.5(a) of the Agreement is hereby amended by replacing “ first
              Additional System ordered within the first twelve (12) months of the
              Term, the
              price shall be the lesser of $ [REDACTED] or
              Xenogen’s then current list price ”
with
              “ first
              Additional System ordered within the first twelve (12) months of the
              Term, the
              price shall be the lesser of $ [REDACTED] or
              Xenogen’s then current list price, and for the second Additional System ordered
              before the first anniversary of the First
              Amendment Effective Date ,
              the
              price shall be the lesser of $ [REDACTED] or
              Xenogen’s then current list price ”.
 
 5.  Amendment
              to Section 3.5 - Payments :
              Section
              3.5 of the Agreement is hereby amended by replacing subsection (b)
              as
              follows:
 
 “(b)  Technology
              License Fee .
              Beginning on the Amendment Effective Date, in addition to the purchase
              price set
              forth in Section 3.5(a), for each Imaging System purchased by Licensee
              hereunder, Licensee shall pay a non-refundable, non-creditable, annual
              technology license fee of [REDACTED] dollars
              ($ [REDACTED] )
              to
              practice the Xenogen Imaging Technology in the Field with the Imaging
              System for
              the first year of the Term and [REDACTED] dollars
              ($ [REDACTED] )
              annually to practice the Xenogen Imaging Technology in the Field with
              each
              Imaging System for each year of the Term thereafter (e.g., for the
              Imaging
              System and an Additional System, an aggregate annual fee of $ [REDACTED] );
              provided however, that if the patents included in the Xenogen Imaging
              Technology
              are declared invalid or unenforceable as they relate to the Imaging
              System in a
              final judicial or administrative opinion from which no appeal can be
              taken, such
              fee shall no longer apply. Annual license fees for each Authorized
              Site shall be
              capped at [REDACTED] dollars
              ($ [REDACTED] ).”
 
 -2-
 6.  Amendment
              to Section 8.1 - Term :
              Section
              8.1 of the Agreement is hereby amended by replacing “will expire three (3) years
              after the System Installation Date (the “Term”)” with “will expire three (3)
              years after the Installation Date of the most recent Additional System
              (the
“Term”).”
 
 7.  Governing
              Law .
              This
              First Amendment shall be governed by, interpreted and construed in
              accordance
              with the laws of the State of California, without regard to conflicts
              of law
              principles.
 
 8.  Counterparts .
              This
              First Amendment may be executed in counterparts, each of which shall
              be deemed
              to be an original and together shall be deemed to be one and the same
              document.
 
 IN
              WITNESS WHEREOF, the Parties hereby execute this First
              Amendment by their respective duly authorized representatives as of
              the First Amendment Effective Date.
 
 XENOGENCORPORATION
                    GENE
                        LOGIC INC.Signature
                    SignatureName
                    NameTitle
                    Title
 
 -3-