Demonstration of Phosphatase in Decalcified Bone

Abstract

As the decalcifying fluids commonly used in histology destroy alkaline phosphatase, it has so far only been possible to demonstrate the enzyme in undecalcified bone. The disadvantages of current methods are threefold: (1) Only bones from embryos or very young animals can give sections sufficiently thin to enable localization of phosphatase to be established satisfactorily by the method of Gomori¹ or of Menten, Junge and Green². (2) If the Gomori method for bone is employed, the preformed phosphate is stained black and the site of phosphatase purple. Controls only show the black bone salt. It is extremely difficult to decide whether there are areas in which both phosphatase and bone salt occur concurrently. (3) The Gomori method suffers from the obvious disadvantage of requiring treatment of the phosphatase-containing tissue with ammonium sulphide (which is an inhibitor of the enzyme³) before and during incubation of the sections.