The PAS staining procedure involves several key steps: fixation of the tissue, oxidation with periodic acid, treatment with Schiff reagent, and counterstaining if necessary. The tissue is first fixed to preserve its structure, then treated with periodic acid to oxidize the glucose moieties to aldehydes. The Schiff reagent reacts with these aldehydes to produce a magenta color, indicating the presence of polysaccharides. A counterstain is often applied to provide contrast and enhance visualization.
