Hi,

A friend of mine is trying to stain carbohydrates with PAS, and he's wondering if anyone has a protocol that works? He has no clue about this method of staining at all.

Thank you.

Here are a couple of protocols that might help.

PERIODIC ACID SCHIFF (PAS) PROTOCOL
PRINCIPLE:
This stain is used for the demonstration of glycogen. Tissue sections are first oxidized by periodic acid. The oxidative process results in the formation of aldehyde groupings
through carbon-to-carbon bond cleavage. Free hydroxyl groups should be present for oxidation to take place. Oxidation is completed when it reaches the aldehyde stage. The aldehyde groups are detected by the Schiff reagent. A colorless, unstable dialdehyde compound is formed and then transformed to the colored final product by restoration of
the quinoid chromophoric grouping.

Link: http://www.jhu.edu/~iic/PDF_protocols/LM/Glycogen_Staining.pdf

PAS - McMANNUS' PERIODIC ACID SCHIFF'S - GLYCOGEN
Link: http://library.med.utah.edu/WebPath/HISTHTML/MANUALS/PAS.PDF