Periodic acid–Schiff is a staining method used to detect polysaccharides such as glycogen, and mucosubstances such as glycoproteins, glycolipids and mucins in tissues.

What is PAS stain used for?

The PAS is most commonly used to demonstrate the thickness of glomerular basement membrane when renal disease is being assessed. The PAS staining procedure is also used to demonstrate hyphae and yeast-forms of fungi in tissue samples due to the high carbohydrate content of the organism's cell walls.

How does the PAS stain work?

PRINCIPLE: The PAS stain is a histochemical reaction in that the periodic acid oxidizes the carbon to carbon bond forming aldehydes which react to the fuchsin-sulfurous acid which form the magenta color. ... Use skin, aorta or normal liver for positive PAS staining. FIXATIVE: Any well fixed tissue.