X0202 4 2004-08-12 0 0001033905 LUMINEX CORP LMNX 0001105966 LOEWENBAUM G WALTER II 1708 WINDSOR AUSTIN TX 78703 1 0 0 0 Common Stock 2004-08-12 4 P 0 6400 6.6312 A 1879433 D Common Stock 2004-08-12 4 P 0 7717 6.6312 A 1887150 D Common Stock 1501792 I See footnote 1,243,208 of these shares are held by Mr. Loewenbaum's wife, Lillian Loewenbaum; 132,586 of these shares are held by a trust for the benefit of Mr. Loewenbaum's children of which Mrs. Loewenbaum is the trustee; and 125,998 of these shares are held by trust for the benefit of Mr. Loewenbaum which has an independent trustee and over which Mr. Loewenbaum neither has nor shares investment or voting power. Mr. Loewenbaum disclaims any beneficial ownership of these securities, except to the extent of his pecuniary interest therein. /S/ G. Walter Loewenbaum II 2004-08-13