Abstract
Modified techniques for the histochemical demonstration of phosphorylase of value in the diagnosis of cancer cells of human gastro-intestinal origin are described. Preservation of the enzyme activity is especially considered; this is facilitated by the use of thoroughly dried cryostat sections. Routine use of these techniques in the clinical laboratory is suggested. Using these procedures, carcinoma ceils of human stomach and intestines stained in 102 of 117 cases; normal control sections of human gastric epithelial cells are regularly unstained.