A modified periodic acid-thiocarbohydrazide-silver proteinate staining sequence for enhanced contrast and resolution of glycogen depositions by transmission electron microscopy

Oxidation of araldite-embedded liver sections by 1% w/v aqueous H₅IO₆ for 15 min and a 5-min reaction of carbonyls with 1% w/v thiocarbohydrazide in 10% v/v acetic acid was employed for subsequent staining of glycogen with silver-proteinate (S-P). The network of branching intracellular glycogen aggregates was revealed by 15-min staining with S-P, whereas 24 hr incubation in S-P was necessary to enhance the contrast of glycogen inclusions. We conclude that the proposed modification of glycogen staining readily affords the means for its localization at a desired level of contrast and resolution.