Malt Diastase And Ptyalin In Place of Saliva in The Identification of Glycogen

Digestion in 1% U. S.P. malt diastase or in 1% ptyalin at 37°C. for 1 hour is an effective substitute for the salivary digestion test used by Bauer, by Bensley and others for the identification of glycogen. Actually the test is not specific for glycogen, since diastase, ptyalin and amylopsin digest other polysaccharides than glycogen, notably starch. In animal tissues this should produce no confusion. Of the two samples tested, the malt diastase proved somewhat more effective than ptyalin and can be fully recommended for sharpness of results.The enzymes should be dissolved in a buffered neutral saline solution consisting of 8g. NaCl, 1.3 g. Na2HPO4 and 0.8 g. NaH2PO4-H2O in 1 liter of water. This solvent by itself does not remove glycogen from liver sections in 1 hour at 37°C.Enzyme tests should be done on uncollodionized sections. Since collodionization permits demonstration of larger amounts of glycogen by both the Best and Bauer methods, this step should be interposed after the digestion test and before the specific glycogen stain.