METACHROMATIC STAINING OF SODIUM BISULFITE ADDITION DERIVATIVES OF GLYCOGEN

In fixed tissues and cell cultures glycogen readily formed sodium bisulfite addition compounds following oxidation with 0.5% aqueous periodic acid. Sodium bisulfite derivatives of oxidized glycogen developed intense metachromasia if stained with 0.5% toluidine blue at the 1.0-5.0 pH range. Induced metachromasia of tissue glycogen was dehydration-labile if the oxidation with periodic acid was carried out for less than 15 min. Oxidation in excess of 15 min resulted in formation of dehydration-resistant metachromasia. The induction of the two types of metachromasia was determined primarily by the duration of oxidation and only secondarily by the duration of addition reaction and sodium bisulfite concentration. The origin of the dehydration-labile metachromasia probably resides with the external glucose units of glycogen depositions, whereas the induction of dehydration-resistant metachromasia may be attributed to the sodium bisulfite derivatives of the internally located glucosyl groups of glycogen.