Blood, 1955, Vol. 10, No. 10, pp. 1023-1029.
© 1955 American Society of Hematology, Inc.
A Histochemical Procedure for Localizing and Evaluating
Leukocyte Alkaline Phosphatase Activity in Smears
of Blood and Marrow
LEONARD S. KAPLOW 1
1 Laboratories of the Mary Fletcher Hospital and the Department of Pathology,
College of Medicine, University of Vermont and State Agricultural College, Burlington,
Vermont.
A rapid and simple method is described for demonstrating the presence of
alkaline phosphatase activity in cells of blood and bone marrow. Smears were
fixed with 10 per cent formalin in methanol at 0 ± 5 C. for 30 seconds and
stained by the azo dye procedure, using propanediol buffer at a pH of 9.6.
A "scoring" technic is outlined, which permits the comparison of alkaline
phosphatase activities of blood leukocytes of different individuals.
Alkaline phosphatase activity was found only in neutrophilic granulocytes
and was localized exclusively in the cytoplasm of these cells. In normal adults,
43 to 95 per cent (mean of 78%) of all neutrophils were unstained. Staining was
up to ten times more intense in smears from patients with a variety of pathologic disorders.
Submitted on February 28, 1955
Accepted on June 25, 1955
