Document:

<PAGE>

                                                                   EXHIBIT 10.13

                               Sublease Agreement

This Sublease Agreement is made this 20th day of December, 1999 at Travis
County, Texas by and between American Innovations, Ltd., (herein "Sublessor"),
and Luminex Corporation, (herein "Sublessee"). Sublessor is the Lessee under
that certain Lease, (the "Main Lease"), by and between Aetna Life Insurance, as
Landlord, (herein "Lessor") and American Innovations, as Tenant, (herein
"Sublessor") executed on or about July 1996, for the premises described in the
Main Lease, (herein, "Leased Premises"). A true and correct copy of the Main
Lease is attached as Exhibit A and incorporated herein by this reference.

In consideration of the mutual promises contained herein and upon the express
condition of the occurrence of a HVAC and mechanical inspection of the Subleased
Premises satisfactory to Sublessee, Sublessor hereby subleases a portion of the
Leased Premises (herein *Subleased Premises*) to Sublessee, subject to the terms
of the Main Lease, and subject further to the provisions of this Sublease
Agreement, as follows:

1.  All the duties and obligations of Sublessee hereunder are expressly
    conditioned on the occurrence of an inspection of the Subleased Premises by
    a licensed heating and air conditioning service company which is
    satisfactory to Sublessee by January 1, 2000. If such an inspection is not
    satisfactory to Sublessee, this Sublease Agreement shall terminate effective
    immediately and all of Sublessee's duties and obligations hereunder shall be
    deemed full and satisfactorily discharged.

2.  Sublessee agrees to abide by and observe all the terms, covenants and
    conditions of the Main Lease.

3.  Insofar as the provisions of the Main Lease do not conflict with the
    specific provisions of this Sublease Agreement each of them is incorporated
    into this Sublease as if completely rewritten herein. Sublessee agrees to be
    bound to Sublessor by all the terms of the Main Lease and to assume towards
    Sublessor and Worm all obligations and responsibilities that Sublessor, by
    the Main Lease, assumes towards Lessor, except for the payment of rent and
    tenant costs by Sublessee to Sublessor, which is governed by Paragraph 5
    herein. Sublessee further agrees to indemnify and hold harmless Sublessor
    from any claim or liability under the Main Lease. The relationship between
    Sublessee and Sublessor shall be the same as between Sublessor and Lessor
    under the Main Lease.

4.  The premises being subleased is identified in Exhibit B and consists of
    approximately 2,500 square feet located within the space leased by Sublessor
    from Lessor and adjoining to space leased by Sublessee from Landlord (the
    "Subleased Premises*). Prior to the execution of this Sublease Agreement
    Sublessee is responsible for ensuring that the Subleased Promises can be
    incorporated with Sublessee's adjoining space while maintaining security
    satisfactory to Sublessor and meeting fire safety code. Any costs related to
    modify the space to comply with security and fire safety shall be the sole
    responsibility of Sublessee. Sublessee may instaIl one (1) door where
    indicated on Exhibit B. Within fifteen (15) days of the end of the Sublease
    Agreement Sublessee shall remove the subject door and repair the wall so
    that the wall is consistent with the surrounding walls. Further, Sublessor
    gives its consent to Sublessee to make interior improvements to the
    Subleased Promises without further approval of Sublessor, limited to the
    addition or alteration of the paint, carpet, telephone and data lines.

5.  The term of this Sublease Agreement shall be for a term of twelve (15)
    months commencing on January 1, 2000 and ending March 31, 2001 provided that
    this Sublease Agreement shall sooner terminate upon the termination for any
    cause whatsoever of the Main Lease. If Sublessee makes any assignment of
    assets for the benefit of creditors, or if a trustee or receiver is
    appointed to administer or conduct its business, or it is judged in any
    legal proceedings to be bankrupt, then this Sublease Agreement shall
    terminate without prior written notice. Unless otherwise terminated as
    specified in this paragraph, this Sublease Agreement shall automatically
    renew each month until termination of the Main Lease or upon ninety (90)
    days written notice by either party, whichever comes first.

6.  Sublessee agrees to pay Sublessor, as rent and tenant costs (including
    electricity) for the Subleased Premises, the sum of two thousand six hundred
    twenty-five dollars ($2,625.00) per month, payable in advance on the 1st day
    of each calendar month during the term of this Sublease. The first monthly
    installment for rent as set forth above shall be due and payable upon
    execution of this Sublease. Upon Execution of this

 American Innovations            Page #1                  Sublease Agreement
<PAGE>

    Sublease, Sublessee shall also deposit with Sublessor the sum of two
    thousand six hundred twenty-five dollars ($2,625.00) as a security deposit
    to be held by Sublessor pursuant to the provisions of the Main Lease.

7.  The following events shall be deemed to be events of default by Sublessee
    under this Sublease: any events of default by Sublessee, listed as events of
    default by Tenant set forth in the Main Lease, or any default in the
    provisions of this Sublease Agreement. Upon the occurrence of any such
    events of default, and in addition to any other available remedies provided
    by law or in equity, Sublessor shall have all remedies granted to Lessor in
    the Main Lease.

8.  Sublessee, shall have no right to assign any interest in this Sublease
    Agreement without first obtaining the written consent of the Lessor and
    Sublessor, which consent may or may not be granted by the Lessor or
    Sublessor in their sole opinion, judgment or discretion.

9.  Sublessor shall have no liability to Sublessee for any wrongful action or
    default on the part of Lessor pursuant to the terms of the Main Lease, and
    Sublessee hereby agrees to look solely to Lessor in event of any such
    default the liability and obligations of Sublessor being solely pursuant to
    the terms and conditions of this Sublease Agreement.

10. Any notice pertaining to this Sublease Agreement or the Main Lease shall be
    in writing and shall be deemed to be delivered on the date it is hand
    delivered to the party to whom such notice is given, or if such notice is
    mailed, on the date on that it is sent by overnight courier or by registered
    or certified mail (postage prepaid, return receipt requested) to the
    respective party at the address listed in the heading of this Sublease
    Agreement.

12. If any provisions hereof shall for any reason be held void or unenforceable,
    the remaining provisions shall remain in full force. Any provisions of this
    Sublease Agreement prohibited by the law of any state shall, as to said
    state, be ineffective to the extent of such prohibition without effecting
    the remaining provisions of this Sublease Agreement This Sublease Agreement
    is governed by the laws of the State of Texas.

13. Except as provided above, no provisions of this Sublease Agreement may be
    waived or modified unless agreed to in writing by both parties. This
    Sublease Agreement constitutes the entire agreement between the parties with
    respect to the subject hereof and supercedes all prior written or oral
    agreements between the parties relating to such subject.

14. Each party represents and warrants to the other that it has the requisite
    authority to enter into this Sublease Agreement and to perform every term,
    provision and obligation of this Sublease Agreement and that neither the
    execution of this Sublease Agreement nor the performance hereunder is in
    conflict with any other agreement.

15. Nothing contained in this Sublease Agreement shall be construed to: a) give
    either party the power to direct or control the day to day activities of the
    other, b) constitute a partnership, joint venture or ownership; or c) allow
    either party to create or assume any obligation on behalf of the other.

16. Should a dispute arise between the parties, every effort will be made to
    resolve the differences by the personnel involved in the dispute. When such
    resolution cannot be achieved, the dispute will be referred to the
    management level of each party. Should all efforts be exhausted without
    satisfactory resolution, then either party may refer the matter to the
    American Arbitration Association for resolution under its rules and
    requirements. Each party shall be responsible for the costs of their own
    witnesses, technical support, lawyers and other assistance. All other costs,
    the timing of the arbitration and the location of the proceedings shall be
    agreed upon mutually and in writing. The parties agree that any matter
    requiring injunctive or temporary relief may be brought in any court having
    jurisdiction.

<TABLE>
<S>                                                       <C>
 ACCEPTED:                                                ACCEPTED:
 American Innovations, Ltd. ("Sublessor")                 Luminex Corporation ("Sublessee")

BY: /s/ Richard J. Smalling                               BY: /s/ James Persky
    --------------------------                               ----------------------
    Richard J. Smalling                                      James Persky
    President                                             Vice President & Chief Financial Officer
    Date: 12/20/99                                        Date: 12/20/99
         ---------                                             ---------
</TABLE>

American Innovations                 Page #2                 Sublease Agreement
<PAGE>

                                          (Separate sublease agreement required)

                              CONSENT TO SUBLEASE
                                   OF LEASE

     This Consent to Sublease of Lease (this "Consent") is executed this 4th day
of January, 2000, by AEtna Life Insurance Company ("Landlord").

                                   RECITALS

     A.   Landlord owns that certain 44,378 square feet located at 12112
Technology Blvd., Austin, Texas, commonly known as McNeil #5 (the "Building").

     B.   American Innovations, Ltd., ("Tenant") is a tenant leasing 24,256 sf
of space in the Building pursuant to that certain lease document by and between
Landlord and Tenant dated June 21, 1996, as amended (the "Lease").

     C.   Tenant desires to sublease a portion of its space, amounting to
approximately 2,500 sf, to Luminex Corporation (the "New Tenant") according to
the terms and conditions of the attached sublease agreement.

     D.   New Tenant has agreed to assume the obligations of Tenant and perform
the obligations thereof as set forth in the Lease pursuant to Sublease Agreement
between American Innovations, Inc. and Luminex Corporation dated as of December
20,1999 (the "Sublease").

                                   AGREEMENT

     Now therefor, for good and valuable consideration, the receipt and
sufficiency of which is hereby acknowledged, the undersigned hereby agree as
follows.

     1.   The above recitals are incorporated herein by this reference.

     2.   Effective upon receipt by Landlord of (i) the executed Sublease, and
(ii) a certificate of insurance indicating that New Tenant carries all of the
insurance coverages required to be carried by Tenant under the Lease. Landlord
hereby consents to the Sublease of the Lease from Tenant to New Tenant pursuant
to the Sublease.

     3.   By acceptance hereof, Tenant acknowledges that Tenant shall be and
remain liable for any claims that Landlord may have under the Lease prior to the
date of the Sublease of the Lease, and New Tenant acknowledges that New Tenant
will assume all obligations under the Lease and be liable for any claims that
Landlord may have under the Lease after die date of such Sublease.

     4.   This consent relates solely to the Sublease and to no other or future
Sublease of the Lease or with respect to any other matter requiring Landlord's
consent under the Lease.
<PAGE>

     5.   Except as otherwise expressly stated, nothing contained herein shall:

          (a)  operate as a representation or warranty by Landlord of any nature
               whatsoever;
          (b)  be construed to modify, waive or affect any of the provisions,
               covenants or conditions of the Lease or to waive any breach
               thereof or any rights of Landlord thereunder or to increase
               Landlord's obligations under the Lease; or
          (c)  release or discharge the Tenant from any liability under the
               Lease and the Tenant shall remain liable and responsible for the
               full performance and observance of all of the provisions,
               covenants and conditions set forth in the Lease on the part of
               the tenant to be performed and observed.

     IN WTTNESS WHEREOF, Landlord has executed this Consent as of the date first
written above.

                                      AEtna Life Insurance Company
                                       By: Allegis Realty Investors LLC, its
                                        [investment advisor and agent]

                                            By:   /s/[ILLEGIBLE]
                                                  --------------------
                                            Name: /s/ [ILLEGIBLE]
                                                  --------------------
                                            Its:  Vice President
                                                  --------------------

ACCEPTED AND AGREED:

American Innovations, Ltd.:

By: /s/ Richard J. Smalling
   -------------------------

Name: Richard J. Smalling

Its: President

Luminex Corporation:

By: /s/ James L. Persky
   -------------------------
Name: James L. Persky

Its: Chief Financial Officer
<PAGE>

                                  EXHIBIT "B"

                            [DIAGRAM APPEARS HERE]<PAGE>

                                                                   EXHIBIT 10.14

             First Amendment to Sublease Agreement between Luminex
           ("Sublessee") and American Innovations, Ltd. ("Sublessor")

          This amendment is to be attached to, and form a part of, the
          Sublease Agreement made the 20/th/ day of December, 1999
          between Sublessor and Sublessee covering a portion of the
          space located at 12112 Technology Blvd., Suite 100, Austin,
          Texas known as McNeil #5 and subject to the Main Lease
          between Sublessor and Aetna Life Insurance.

1.   The premises being subleased is amended as shown in Exhibit A to include an
     additional 400 square feet comprising a hallway that will serve as the fire
     exit pathway for said premises. Any costs related to modify the additional
     space to comply with security and fire safety shall be the sole
     responsibility of Sublessee. Sublessee is responsible for installing two
     doors where indicated on Exhibit A; one door will separate the premises
     being subleased from those being leased by Sublessor and the second door is
     required to open the additional hallway covered by this amendment.

2.   Sublessee agrees to pay Sublessor rent and tenant costs (including
     electricity) for the premises being subleased, including the additional 400
     square feet described in this amendment, in the amount of three thousand
     forty-five dollars ($3,045.00) per month payable in advance on the 1/st/
     day of each calender month during the term of the Sublease Agreement. Upon
     execution of this amendment, Sublessee shall pay Sublessor $420 to cover
     the difference in rent and tenant costs for the additional 400 square feet
     in January 2000.

3.   The term of the Sublease Agreement shall be for fifteen (15) months
     commencing on January 1, 2000 and ending March 31, 2001 provided that the
     Sublease Agreement shall sooner terminate upon the termination for any
     cause whatsoever of the Main Lease. The amendment is made to correct a
     typographical error in the Sublease Agreement.

4.   Addresses were omitted from the Sublease Agreement. For the purposes of
     Section 10 of the Sublease Agreement, any notices shall be delivered to the
     following addresses:

          American Innovations                        Luminex Corporation
          12112 Technology Blvd., Suite 100           12212 Technology Blvd.
          Austin, Texas 78727                         Austin, Texas 78727

Except as herein modified and amended, the Sublease Agreement shall remain in
full force and effect and all the terms, provisions, covenants and conditions
thereof are hereby confirmed:

ACCEPTED:                                   ACCEPTED:
American Innovations, Ltd. ("Sublessor")    Luminex ("Sublessee")

BY: /s/ Richard J. Smalling                 BY: /s/ James L. Persky
    --------------------------------            --------------------------------
    Richard J. Smalling                         James Persky
    President                                   Vice President & Chief Financial
    Date: January 24, 2000                      Officer
                                                Date:___________________________

                                   Page #1

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00001-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00001-of-00352.parquet"}]]