Dehydration and paraffin embedding of tissues

Wolf D. Kuhlmann

Division of Radiooncology, Deutsches Krebsforschungszentrum, 69120 Heidelberg, Germany

Laboratory Diagnostics & Cell Science, 56112 Lahnstein, Germany

The purpose of embedding biological specimens is to replace water by a matrix which is sufficiently stable to maintain cell structures. For this purpose, tissue blocks are first stabilized by fixatives. Then, specimens are dehydrated and embedded in paraffin wax which is the typical embedding medium for routine histology. A modern paraffin embedding medium is Paraplast®. Paraplast is a highly purified paraffin with a melting point of 56ºC and formulated to give outstanding tissue infiltration and superior quality sections. Typical paraffin embedding schedules are described.