This document discusses diagnostic cytopathology and provides information on techniques used in cytopathology. It defines cytopathology as the study and diagnosis of diseases on the cellular level by interpreting cells that have exfoliated spontaneously or been obtained from organs/tissue. The document outlines sample collection methods, smear preparation techniques, fixation, staining methods, and the applications of cytopathology in identifying infections, cancers, and other diseases. It describes exfoliative and interventional cytology techniques such as fine needle aspiration cytology.