Glycogen staining is one of the conventional staining methods in pathology. McManus was the first to use the PAS technique to show mucins in 1946. This technique is commonly used to show glycogen and other polysaccharides. As well as cartilage, pituitary, mold, fungus, pigment, amyloid, basement membrane and so on.

Oxidants can oxidize 1, 2-glycol groups in sugars and related substances, making it into dialdehyde, aldehyde and Schiff reagent can combine to form a magenta compound, producing purple red. Since oxidants can also oxidize other substances in cells, it is very important to choose the concentration and oxidation time of oxidants so that the oxidation control can oxidize ethylene glycol group into aldehyde group without peroxidation.