Jay Johnston and Gerard Vaillant have joined the board of directors of Luminex, the Austin, Texas-based company said last week. Laurence Hirsch and Thomas Caskey will retire from the board before the summer.

Johnston is chairman of QuesTek Innovations. In the past, he was corporate vice president for diagnostic assays and systems at Abbott Laboratories. He holds an MBA in general management from Amos Tuck School of Business Administration and an AB degree in public administration from Dartmouth College.