A cytochemical scanning electron microscopy study of non-specific acid esterase and acid phosphatase activities in human peripheral blood lymphocytes.

We analyzed the distribution patterns of nonspecific acid esterase and acid phosphatase activities with cytochemistry-scanning electron microscopy in backscattered and secondary electron imaging modes in isolated normal human peripheral blood lymphocytes. The analysis of non-specific acid esterase activity in the backscattered electron imaging mode showed, in some cells, focal distribution with a well-defined, homogenous deposit. Two patterns of acid phosphatase activity were evident with the backscattered electron imaging mode, i.e., focal and granular. Peripheral blood lymphocytes showing focal activity of both enzymes presented a smooth surface with few scattered microvilli as seen with the secondary electron imaging mode; while lymphocytes with a granular pattern of acid phosphatase activity had abundant microvilli. The correlation between patterns of enzymatic activity as seen in backscattering electron imaging mode, and surface morphological features as seen with secondary electron imaging mode, distinguished a subpopulation of lymphocytes of T lineage in human peripheral blood.