A Paraffin Method for Refractory Plant Materials

A modification of Zirkle's n-butyl alcohol method for dehydrating refractory plant material and embedding it in paraffin is described. The material is cut into small pieces and killed and fixed in CRAF III. It is dehydrated in Zirkle's n-butyl alcohol series, slightly modified. Infiltration is accomplished by adding chips of paraffin of low melting point (52°C.) to the bottle containing butyl alcohol and the tissues at a gradually increasing series of temperatures. The butyl-alcohol-paraffin mixture is gradually replaced by pure paraffin (melting point 56-58°C). The material is embedded in Fisher Tissuemat (56-58°C). Before microtoming, the block of embedded tissue is trimmed so that part of the specimen is exposed, and it is soaked in water until it cuts easily.