APAAP labelling of blood and bone-marrow samples for phenotyping leukaemia.

The reliability of labelling routinely prepared air-dried peripheral-blood and bone-marrow smears with the alkaline-phosphatase/anti-alkaline-phosphatase (APAAP) method for phenotyping leukaemias was evaluated in 259 cases of haematological malignancy. All the cellular markers currently used in leukaemia diagnosis could be detected with this technique. Since the technique can be used on blood and marrow smears even after storage or postal transport, it is suggested that APAAP labelling should become the method of choice for immunophenotyping neoplastic samples in many haematology laboratories not equipped with specialised immunological diagnostic facilities. The method should also be valuable for epidemiological studies of leukaemia.