Test Details: Periodic acid schiff (PAS) is a staining method used to detect polysaccharides such as glycogen and mucosubstances such as glycoproteins, glycolipids and mucins in tissues. It can be used to assist in the diagnosis of several medical conditions like Glycogen storage disease, Paget disease of the breast, Alveolar soft part sarcoma, Whipple's disease, 1-antitrypsin deficiency, fungal infection etc. It can detect glycogen granules which may also be visible in tumours of the bladder, kidney, ovary, pancreas, and lung.