A New Maraglas, D.e.r.® 732, Embedment for Electron Microscopy

A new epoxy embedding mixture for biological material recently has been introduced by Freeman and Spurlock (1). This mixture consists of Mara-glas 655, Cardolite NC-513, dibutyl phthalate, and the curing agent benzyldimethylamine (BDMA). Maraglas has certain advantages over other resins and epoxies, notably, wide range of miscibility, low viscosity, ease of sectioning, good staining qualities, beam stability, and little background granularity. Although improvements have been made in the original technique (2), certain problems remain. The Maraglas mixture penetrates tissue very slowly, makes the tissue quite brittle, and has variable polymerization properties. In this paper the use and advantages of a new polyglycol type flexibilizer as a replacement for Cardolite NC-513 in a Maraglas 655 epoxy formulation will be presented.