.
                                                                               .
                                                                               .
                                                                     EXHIBIT 5.1

                             BASS, BERRY & SIMS PLC
                    A PROFESSIONAL LIMITED LIABILITY COMPANY
                                ATTORNEYS AT LAW

                                                                            
         KNOXVILLE OFFICE                                                               DOWNTOWN OFFICE:
 900 SOUTH GAY STREET, SUITE 1700                    REPLY TO:                           AMSOUTH CENTER
       KNOXVILLE, TN 37902                        AMSOUTH CENTER                  315 DEADERICK STREET, SUITE 2700
          (865) 521-6200                 315 DEADERICK STREET, SUITE 2700            NASHVILLE, TN 37238-3001
                                             NASHVILLE, TN 37238-0002                   (615) 742-6200
          MEMPHIS OFFICE                          (615) 742-6200
    THE TOWER AT PEABODY PLACE
   100 PEABODY PLACE, SUITE 950                  www.bassberry.com                     MUSIC ROW OFFICE:
      MEMPHIS, TN 38103-2625                                                          29 MUSIC SQUARE EAST
          (901) 543-5900                                                            NASHVILLE, TN 37203-4322
                                                                                         (615) 255-6161




                                September 2, 2004


Luminex Corporation
12212 Technology Boulevard
Austin, Texas 78727

         Re: Registration Statement on Form S-8

Ladies and Gentlemen:

         We have acted as your counsel in the preparation of the Registration
Statement on Form S-8 (the "Registration Statement") relating to the Balthrop
Non-Qualified Stock Option Agreement (the "Plan") filed by you with the
Securities and Exchange Commission covering an aggregate of 500,000 shares (the
"Shares") of common stock, $.001 par value, issuable pursuant to the Plan.

         In so acting we have examined and relied upon such records, documents,
and other instruments as in our judgment are necessary or appropriate in order
to express the opinions hereinafter set forth and have assumed the genuineness
of all signatures, the authenticity of all documents submitted to us as
originals, and the conformity to original documents of all documents submitted
to us as certified or photostatic copies.

         Based on the foregoing, we are of the opinion that the Shares, when
issued pursuant to and in accordance with the Plan, will be validly issued,
fully paid, and non-assessable.

         We hereby consent to the use of this opinion as an exhibit to the
Registration Statement.

                                               Very truly yours,



                                               /s/ Bass, Berry & Sims PLC