A triple stain technique to evaluate monocyte, neutrophil, and eosinophil proliferation in soft agar cultures

A useful cytochemical technique has been developed which facilitates the identification of the types of cell aggregates which proliferate in soft agar cultures of hematopoietic stem cells. Staining of fixed agar discs for alpha-naphthyl acetate esterase (ANAE), naphthol AS-D chloroacetate esterase (CAE) and with Luxol fast blue (LFB) in sequence results in permanent preparations in which monocytic, neutrophilic and eosinophilic aggregates can readily be distinguished on the same slide. This represents an improvement over the currently used technique which relies on the removal of a representative sample of aggregates from the agar discs for cell typing. Whole plate staining results in more accurate estimates of eosinophil growth since the frequency of occurrence of these cell aggregates is low under many of the culturing conditions used. The technique provides a useful tool for studying normal and abnormal hematopoiesis.