Paraffin Sections

All paraffin embedded tissue is cut at a thickness of 3-5 µm. Thicker sections make morphological assessment much more difficult. The sections are floated on a warm water bath (45°C), before being picked up onto microscope slides and allowed to drain. Sections for tinctorial staining are placed on a hot plate (56°C) for 15 minutes before staining. Sections for immunocytochemical staining are picked up on aminopropyltriethoxysilane (APES) coated slides and dried overnight in an incubator at 37°C.

One section cut from each paraffin block is stained with haematoxylin and eosin (H&E). After initial examination of the H&E section either additional tinctorial stains (for example, Gordon and Sweet's reticulin stain) or specific panels of immunocytochemical markers may be performed.