Experiments on the Silver Nitrate Method for the Histological Demonstration of Ascorbic Acid (Vitamin C)

ABSTRACT A 10 % solution of silver nitrate in 10 % acetic acid has been widely used to show the presence of ascorbic acid in microscopical preparations (Bourne, 1936; Giroud, 1938). When there is ascorbic acid in the cells a black precipitate of metallic silver is obtained. This precipitate is often observed to be on or in the Golgi material, and it has been supposed that where this is the case the ascorbic acid is itself located in the Golgi substance (Giroud, 1938; Bourne, 1935). However, it has been pointed out that this conclusion is not necessarily correct, since the localization of the silver precipitate may be a physico-chemical phenomenon, resulting from the presence of a certain type of interface (Barnett, 1942). Experiments have therefore been carried out in vitro to investigate whether silver precipitates tend to accumulate at interfaces in conditions comparable with those in cells.