HIS REPORT deals with the histochemical T demonstration of alkaline phosphatase activity in tissue sections of 87 benign and malignant tumors and various inflammatory gastrointestinal diseases. Alkaline phosphatase was demonstrated with a simultaneous azo dye coupling method.
Methods
Representative blocks 3-mm. thick were cut from surgical specimens 15 minutes to 4 hours after operation and immersed in 10% cold (4' C.) neutral Formalin. A few specimens were obtained at autopsy.
After fixation at 4 O C. for 16 to 24 hours, frozen sections 15 p in thickness were stained for alkaline phosphataste using a simultaneous coupling azo dye method.14.15 Upon incubation for 15 minutes at PH 9.1 with the substrate Naphthol AS phosphate, the naphthol AS liberated by enzymatic hydrolysis reacted promptly with a stabilized diazonium salt (fast blue BBN) dissolved in the substrate solution to yield a bright-blue extremely insoluble azo dye that precipitated at the sites of enzymatic hydrolysis. Alkaline phosphatase activity was graded arbitrarily from a slight to a n intense reaction by estimating visually under the low power of the microscope the over-all color density of the tissue.
RESULTS
Alkaline phosphatase activity was generally confined to the stromal elements of tumors as
From the Yamins Laboratory for Surgical Research and the departments of