HISTORADIOGRAPHIC IDENTIFICATION OF ALKALINE PHOSPHATASE

Abstract

The site of deposition of calcium phosphate in the Gomori-Takamatsu method for the identification of alkaline phosphatase has been studied using historadiographic methods. Frozen sections of rat kidney were immersed in the substrate for the enzyme and then mounted on small pieces of X-ray plate. After drying, the specimen and plate were exposed to X-ray wavelengths of 12 A. The calcium phosphate produced from the substrate by the enzyme absorbed the X-rays strongly and a good image of its localization was obtained on the plate. It was also found possible to convert the calcium phosphate to cobalt phosphate and then to cobalt sulphide and to localize these compounds by the X-ray method. The possible value of the method for quantitative studies on products of enzymically controlled reactions is discussed.