Abstract

A brief history of tissue embedding as applied to transmission electrón microscopy is given. Perhaps the first successful embedding matrix was a mixture of methyl and n-butyl methacrylate. This formulation penetrated tissues well and was easy to section with the glass knives available at the time, but tissue preservation was sometimes marginal. Mcthacrylates were followed by epoxy resins which gave much better tissue preservation although they were more difficult to section and did not penétrate tissue as well. Epoxy resins are today the dominant embedding resin. More recently. resins particularly suited for ímmunocytochemistry have become popular. The most notable of these are LR White and Lowicryl. Advances in freezing techniques have also made vitreous ice a viable embedding matrix for many applications.