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                                                                   EXHIBIT 10.23

                         CONSULTING SERVICES AGREEMENT

CONSULTING SERVICES AGREEMENT, dated as of July 30, 1999, by and between
SpectruMedix Corporation, a Delaware corporation (the "Company"), located at
2124 Old Gatesburg Road, State College, Pennsylvania 16803, and The
Perkin-Elmer Corporation, a New York corporation and wholly-owned subsidiary of
PE Corporation, ("Perkin-Elmer") with offices at 850 Lincoln Centre Drive,
Foster City, CA 94404.

                                  W I T N E S S E T H:
                                  - - - - - - - - - -

WHEREAS, Company engages in research and development of instrumentation used in
the field of *****;

WHEREAS, concurrently herewith, the Company and PE Corporation are entering into
that certain Stock Purchase Agreement concerning the purchase of shares of
preferred stock of the Company (the "Stock Purchase Agreement"); and

WHEREAS, in connection with the Stock Purchase Agreement, the Company has agreed
to provide certain consulting services to Perkin-Elmer;

NOW, THEREFORE, in consideration of the premises and of the mutual
representations, warranties and agreements set forth herein, the Company and
Perkin-Elmer agree as follows:

1.   Services. During the Term (as defined below), Company shall provide
     --------
consulting services to Perkin-Elmer in the area of ***** as may be reasonably
requested by Perkin-Elmer upon reasonable notice (the "Services").

2.   Fees. The fee for such Services shall be Two Million Dollars($2,000,000.00)
     ----
payable in full as of the date hereof by wire transfer to an account designated
by the Company.

3.   Expenses. Perkin-Elmer shall reimburse Company for its reasonable expenses
     --------
associated with the rendering of the Services, provided, however, that Company
is not authorized to incur any expenses on behalf of Perkin-Elmer without prior
written consent of and authorized agent of Perkin-Elmer, and that all statements
submitted by Company for services and expenses shall be in the form prescribed
by Perkin-Elmer.

4.   Term. The term of this Agreement shall be three (3) years following the
     ----
date hereof (the "Term"). Sections 5, 6, 7 and 8 shall survive the termination
or expiration of this Agreement.

5.   Confidentiality. Company shall not, either during or subsequent to the Term
     ---------------
of this Agreement, directly or indirectly divulge to any third party any
information designated confidential by Perkin-Elmer; nor shall it disclose to
anyone other than an employee of Perkin-Elmer or use in any way other than in
the course of the performance of this Agreement any confidential information
regarding Perkin-Elmer, including Perkin-Elmer's know-how not known to the
general public or recognized as standard practice, whether acquired or developed
by Company, either during or subsequent to the Term of this Agreement, directly
or indirectly publish any such information without prior written authorization
from Perkin-Elmer to do so. Company shall protect such information to prevent
its unauthorized use, disclosure or

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publication using the same degree of care as Company uses to protect its own
information of similar nature, but in no event less than a reasonable degree of
care. The confidentiality obligations of this Agreement shall not apply to
confidential information which (a) was in the Company's possession before
acquisition of such information from Perkin-Elmer; (b) is or becomes a matter of
public knowledge through no fault of the Company; or (c) is rightfully received
by the Company from a third party without a duty of confidentiality.

6.   Perkin-Elmer Property.  When requested by Perkin-Elmer and in any event
     ---------------------
upon the termination or expiration of this Agreement, Company shall return to
Perkin-Elmer any Perkin-Elmer property that has come into its possession during
the Term of this Agreement, unless Company has received written authorization
from Perkin-Elmer to keep such property.  The product of all work performed
solely in connection with this Agreement at Perkin-Elmer's direction, including
reports, drawings, computer programs, devices or models, shall be the property
of Perkin-Elmer or its nominees, and Perkin-Elmer or its nominees shall have the
sole right to use, sell, license, publish, or otherwise disseminate or transfer
rights in such work product.

7.   Inventions.  During and subsequent to the Term of this Agreement, Company
     ----------
shall communicate to Perkin-Elmer's Intellectual Property Counsel all inventions
made or conceived in connection with any projects or work assignment performed
solely and exclusively for Perkin-Elmer at Perkin-Elmer's direction; and without
further consideration, Company will assign all right, title and interest in such
inventions to Perkin-Elmer and assist Perkin-Elmer and its nominees in every
proper way, entirely at Perkin-Elmer's expense, to obtain appropriate
intellectual property protection for these inventions in any and all countries,
all such inventions to be and to remain the property of Perkin-Elmer or its
nominees, whether patented or not.

8.   Copyrights.  Company shall, during and subsequent to the Term of this
     ----------
Agreement, without further consideration, assign all right, title and interest
in any copyrightable material produced solely in connection with this Agreement
at Perkin-Elmer's direction and will assist Perkin-Elmer and its nominees in
every proper way, entirely at its expense, to secure, maintain, and defend for
its own benefit, copyrights and any extensions and renewals shall be and remain
the property of Perkin-Elmer, whether copyrighted or not.  All material produced
by Company solely in connection with this Agreement at Perkin-Elmer's direction
shall be considered "Work Made for Hire" insofar as may be permitted by the
laws governing copyright.

9.   Prior Knowledge and Inventions.  With respect to all subject matter
     ------------------------------
including ideas, processes, designs, and methods which Company discloses or uses
in the performance of this Agreement, Company warrants that it has the right to
make such disclosure and use thereof without liability to others.

10.  Use of Names.  Neither party shall at any time employ the name or any of
     ------------
the trade names, trademarks, slogans, designs, or like the of the other party
for any advertising, promotional or other purposes without prior written
permission to do so.

11.  No Agency Relationship.  This Agreement does not, shall nor be deemed to,
     ----------------------
make either party hereto the agent or legal representative of the other for any
purpose whatsoever.  Neither party shall have the right or authority to assume
or create any obligations or responsibility whatsoever, express or

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implied, on behalf of or in the name of the other, or to bind the other in any
respect whatsoever.

12.  Independent Contractor. In making and performing this Agreement, Company
     ----------------------
shall act at all times as an independent contractor and nothing contained in
this Agreement shall be constructed or implied to create between Company and
Perkin-Elmer an agency, partnership, or employee-employer relationship, or to
create between Company and Perkin-Elmer any other form of legal association or
arrangement which imposed liability upon one party for the act or failure to act
of the other party.

13.  Assignment. Company may not assign or otherwise transfer of any of its
     ----------
rights or obligations under this Agreement without the prior written consent of
Perkin-Elmer.

14.  Successors and Assigns. This Agreement shall be binding upon, enforceable
     ----------------------
against and inure to the benefit of, the parties hereto and their respective
heirs, administrators, executors, personal representatives, successors and
assigns, and nothing herein is intended to confer any right, remedy or benefit
upon any other person or entity.

15.  Governing Law; Submission to Jurisdiction. This Agreement shall in all
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respects be governed by and construed in accordance with the laws of the State
of New York applicable to agreements made and fully to be performed in such
state, without giving effect to conflicts of law rules or provisions (whether of
the State of New York or any other jurisdiction) that would cause the
application of the laws of any jurisdiction other than the State of New York.
The parties hereto agree to submit to the jurisdiction of the state and federal
courts in the State of New York with respect to any claim or matter arising
under this Agreement, and hereby consent that service of process with respect to
all courts in and of the State of New York may be made by registered mail to
such party at the address of such party set forth herein.

16.  Counterparts. This Agreement may be executed in multiple counterparts,
     ------------
each of which shall be deemed an original, but all of which together shall
constitute one and the same instrument.

17.  Construction. Headings contained in this Agreement are for convenience
     ------------
only and shall not be used in the interpretation of this Agreement. References
herein to sections and exhibits are to the sections and exhibits, respectively,
of this Agreement. The exhibits are hereby incorporated herein by reference and
made a part of this Agreement. As used herein, the singular includes the plural,
and the masculine, feminine and neuter gender each includes the others where the
context so indicates.

18.  Severability. If any provision of this Agreement is held to be invalid or
     ------------
unenforceable by a court of competent jurisdiction, this Agreement shall be
interpreted and enforceable as if such provision were severed or limited, but
only to the extent necessary to render such provision and this Agreement
enforceable.

19.  Non-Solicitation. During the Term and for a period of one (1) year
     ----------------
thereafter Perkin-Elmer shall not solicit, induce or attempt to solicit or
induce any employee of the Company to become an employee of Perkin-Elmer or its
affiliates other than through general solicitations not directed to specific
individuals or companies.

20.  Entire Agreement. This Agreement and any schedules and exhibits thereto,
     ----------------
sets forth the entire

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understanding of the parties hereto with respect to its subject matter, merges
and supersedes all prior and contemporaneous understandings with respect to its
subject matter and may not be waived or modified, in whole or in part, except by
a writing signed by each of the parties hereto. No waiver of any provision of
this Agreement in any instance shall be deemed to be a waiver of the same or any
other provision in any other instance. Failure of any party to enforce any
provision of this Agreement shall not be construed as a waiver of its rights
under such provision.

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IN WITNESS WHEREOF, each of the parties hereto has executed this Agreement as of
the date first set forth above.

                                        COMPANY:

                                        SPECTRUMEDIX CORPORATION


                                        By: /s/ Joseph K. Adlerstein
                                            ---------------------------------
                                        Name:  Joseph K. Adlerstein
                                               ------------------------------
                                        Title: Chief Executive Officer
                                               ------------------------------


                                        THE PERKIN-ELMER CORPORATION


                                        By: /s/ Michael W. Hunkapiller
                                            ---------------------------------
                                        Name:  Michael W. Hunkapiller
                                               ------------------------------
                                        Title: Senior Vice President
                                               ------------------------------

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