The Histochemical Demonstration of Glycogen by Silver Complexes

Abstract

Any combination of acid hydrolysis and oxidation can activate the carbohydrate: there is no specific agent. The best results were with chromic acid. The suggestion is made that periodic acid hydrolysis can yield equally good results in shorter time. Ammoniacal silver carbonate was the best of the complexes studied because it stains rapidly, is economical, stable and easy to prepare. Direct or indirect (with formol reduction) reactions can be chosen when working with ammoniacal silver carbonate complexes. The following procedures are proposed: a) hydrolysis with 10% chromic acid, 20-30 min; b) immerse in the following complex: 10% aqueous AgNO3, 4 ml.; satd. soln. of lithium carbonate, to 20 ml.; drop concd. Nh4OH until almost completely dissolved (leave a light turbidity); complete to 100 ml. with a sat. sol. of lithium carbonate; let stand and filter. Store in a brown glass well-stoppered bottle. The slides can either be exposed 15 min. at room temp. in this complex and reduced with 2% neutral formol for about 30 sec., or incubated during 50-60 min. in a 10% soln. of the complex at 45-50[degree]C followed by a thorough washing with water. Tone with 1:500 gold chloride and finish as usual. Collodion coating and formol alcohol or picro-formol-alcohol-acetic fixation are essential in direct reactions.