Tissue Processing, Embedding and Sectioning

Tissue processing

We process fixed tissue samples using a Leica TP1020 Automatic Tissue Processor. This prepares tissue samples for embedding in paraffin wax by taking the tissue through three steps; dehydration in alcohol, clearing in xylene and finally, infiltration with paraffin wax. Our most commonly used protocol is approximately 12 hours long.

Embedding

We embed processed tissue samples using the Histostar Tissue Embedding System. The processed tissue is orientated within a metal mould which is then filled with molten paraffin wax. A labelled cassette is then placed on top and also filled with wax. The mould is then transferred to a cold plate to set before it can be removed to expose the final paraffin embedded tissue block.

Histostar Tissue Embedding System

Paraffin embedded tissue block

Sectioning

We section tissue blocks using a Leica RM2235 rotary microtome. The paraffin embedded tissue block is placed in the microtome and the wax trimmed away until the tissue is exposed. Thin sections of the block are then cut, placed on the surface of a water bath and transferred onto a slide.