A CRITICAL EXAMINATION OF THE GOMORI METHOD FOR ALKALINE PHOSPHOMONOESTERASE

Abstract

The fixatives tested were alcohol, acetone and a 10% formalin-alcohol soln. The last-mentioned fixative was not suitable. 90% alcohol gave the best results. The procedures of fixation and embedding can be successfully reduced to about 24 hrs. by the following technique: (1) Fixation in 2 changes of 90% alcohol for 24 hrs., followed by exposure to 96% alcohol for 1 hr. (2) Two exposures to absolute alcohol, 15 min. each. (3) Two exposures to benzene, 15 min. each. (4) Three exposures to paraffin at 55[degree]C, 20 min. each. (5) Embedding. Sections treated in this manner and deparaff inized before incubation show almost the same grade of staining as frozen sections. In order to avoid diffusion of the enzyme during incubation, the time of storage in the substrate fluid should not be too long. In the material studied including endometrium, testis and rat kidney, incubation for 1 to 2 hrs. gave opt. reactions. Sections treated with a citrate buffer soln. at pH5 before incubation only showed traces of activity. For accurate and uniform results, the substrate fluid should never be used more than once as this may interfere markedly with the reactive capacity of the fluid.