The primary purpose of using PAS with diastase staining procedure is to differentiate glycogen from other PAS-positive elements, such as mucin, that may be present in the tissue sample. Mucin can be identified explicitly in specific tissue samples using the PAS staining procedure only if the glycogen (which is also PAS-positive) is digested with diastase and washed out.
Several enzyme deficiencies can be diagnosed by analyzing glycogen deposits in the liver.
The PAS with diastase staining procedure can also differentiate glycogen granules from others in various tumor types.
