Ultrastructural localization of acid phosphatase in immunologically defined neoplastic lymphocytic cells and hairy cells A comparison between two different substrates

Abstract

The subcellular localization of acid phosphatase (AcP) in various immunologically‐defined neoplastic lymphoid cells including hairy cells was investigated by electron microscopy. 2 substrates, naphthol‐AS‐BI‐phosphoric acid (naphthol‐AS‐BI‐P) and sodium β‐glycerophosphate, were compared. By incubation in naphthol‐AS‐BI‐P containing medium, the reaction product was found located in granules, vesicles, the Golgi apparatus, the rough ER including the nuclear envelope in the cells of T ALL, T CLL and HCL. A typical pattern of reaction was observed for each of these disorders: enzyme‐positive Golgi membranes and neighbouring granules, clustered in the nuclear notch in T cell‐derived lymphoblasts; enzyme‐positive granules around Gall bodies, aggregated paranuclearly in T CLL lymphocytes and enzyme‐positive scattered cytoplasmic granules and vesicles in hairy cells. Enzyme activity was occasionally seen in singly‐occurring granules in the cells of cALL, B CLL and B PLL, rarely in other substructures. With the Gomori method using β‐glycerophosphate as substrate, the enzyme reaction was limited primarily to lysosomal sites and was seldom observed in other organelles. Tartrate‐resistant AcP was found in the majority of hairy cells and in a few prolymphocytes, located in the same structures as AcP without tartrate.