P.A.S. Diastase - 1704

The PAS kit Diastase is indicated for glycogen digestion.

In PAS staining, periodic acid selectively attacks the hydroxyl, 1,2-glycolic, hydroxyamino, and primary and secondary amino groups, causing the bond between two adjacent carbon atoms to break and the release of the aldehyde group, which is then detected with Schiff reagent.

Tissue compounds, which possess these free groups and in quantities sufficient to be detected, are polysaccharides, mucins, glycoproteins, glycopeptides, glycosaminoglycans, glycolipids, but also unsaturated lipids and phospholipids (such as sphingomyelin) which undergo oxidation of conjugated double bonds with the formation of two hydroxyl groups which are further oxidized to aldehydes. 

Instead, diastase acts selectively only on glycogen, breaking it down into simpler sugars. In this way, glycogen visualization is possible by comparing two slides, the one treated with diastase will be free of glycogen. Enzymatic digestion of glycogen also allows us to highlight neutral mucins following the PAS reaction.