AbstractAcrylic resin mixtures are now widely used as embedding media for the preparation of tissue sections. Most of these mixtures are based on 2-hydroxyethyl methacrylate (glycol methacrylate, GMA). Resin embedding preserves tissue components far better than paraffin, celloidin or frozen sections. The present review describes the basic principles and trouble shooting, in particular: the chemical and physical properties of GMA, and components used for GMA mixtures; fixation of tissues for resin embedding; methods for dehydration; microtomy; stretching on water and mounting in relation to the final dimensions of GMA sections; staining of GMA 3embedded tissue sections; and the use of GMA resins in immunohistochemistry. In addition, standard, step by step procedures for embedding tissues in GMA is included. (The J Histotechnol19:297–311, 1996)