Abstract
Acid phosphatase and beta-glucuronidase activities have been determined cytochemically in T, B and null lymphocytes as part of an effort to charaterize the human haemopoietic stem cell. A combination of weak acid phosphatase activity and strong beta glucuronidase staining, in the form of a single large granule, has been shown to be specific for T cells. On the basis of this approach alone, non-T cells could not be further subclassified. Further cytochemical evaluation is being explored.