This technical program provides a detailed examination of tissue fixation, the foundational step in histopathological analysis. It covers essential definitions, the various chemical and physical actions of fixatives, and their primary functions in preserving cellular structure. Participants will explore the specific mechanisms of cross-linking, the role of buffers, and the factors that influence penetration and fixation quality. The curriculum also details the selection of reagents for different tissue types and diagnostic requirements, providing lab professionals with the expertise needed to prevent autolysis and ensure high-quality diagnostic sections.