Tissue Sampling and Processing for Histopathology Evaluation.

Histological procedures aim at providing good-quality sections that can be used for a light microscopic evaluation of tissue. These are applicable to identify either spontaneous or diseases-induced changes. Routinely, tissues are fixed with neutral formalin 10%, embedded in paraffin, and manually sectioned with a microtome to obtain 4-5 μm thick paraffin sections. Dewaxed sections are then stained with HE&S (hematoxylin-eosin and saffron) or can be used for other purposes (special stains, immunohistochemistry, in situ hybridization, etc.). During this processing, many steps and procedures are critical to ensure standard and interpretable sections. This chapter provides key recommendations to efficiently achieve this objective.