Observations on the phosphatase content of blood and bone marrow cells in normal and pathologic hemopoiesis.

By WILLIAM KERPPOLA, M.I).* P HOSPHATASE can be demonstrated in tissues by means of reliable histochemical methods. Such a method! w’as described for alkaline phosphatase in 1939 by Gomori,#{176}’ and in the same year by Takamatsu.2 Two years later Gomori#{176} described his method for demonstrating acid phosphatase. The principle on which these methods are based is to incubate slices of tissue with glycerophosphate ; the phosphate is then liberated by phosphatase. The phosphate is converted through calcium chloride into calcium phosphate, and through a soluble cobalt or lead compound into the corresponding phosphate. This is precipitated w’ith ammonium sulfide as black-brown cobalt sulfide or black lead sulfid!e. The former is used for d!emonstratmg alkaline phosphat.ase, the latter for localizing acid phosphatase. Previous studies of blood and bone marrow’ by this technic have been few’ in