Staining Techniques

Abstract

Standardization of staining techniques is a prerequisite for obtaining reproducible slides, a necessity for reliable diagnoses. Only a limited number of slides can be obtained from transbronchial and bronchial biopsies due to their small size. Bronchial biopsies being a little bit larger than transbronchial biopsies, they are mostly employed for confirmation or exclusion of malignancies. PAS stain is the most useful one in bronchial biopsies in addition to the classic hematoxylin eosin, especially for separating small cell anaplastic carcinoma from undifferentiated non-small cell carcinoma such as adenocarcinoma or epidermoid carcinoma. It is employed for delineating basement membranes, for demonstrating the presence of organisms, especially fungus, and for assessing extracellular fluids. To demonstrate the nature of inflammatory cells and to separate them from malignant ones, the Romanowsky-Giemsa stain is the most useful.