THE ROLE OF HISTOCHEMICAL AND BIOCHEMICAL PREPARATION METHODS FOR THE DETECTION OF GLYCOGEN

Abstract

Block fixation for the histochemical demonstration does not safely preserve glycogen. Even when using "glycogen fixatives" and low temperatures the staining measured intensity does not correspond to the amount of glycogen measured chemically. Adequate preservation is obtained only with quenching. Lyo- and desmoglycogen fractions in biochemical assays are obtained when coarse tissue homogenates are extracted with TCA, while from fine homogenates the same glycogen amount can be extracted with TCA as with KOH digestion of the tissues. The histochemical demonstrability of glycogen in fixed tissue blocks does not depend on the presence of lyoglycogen.