A method for the differentiation of T and B lymphocytes and monocytes migrating under agarose

This report describes alterations in the agarose lymphocyte migration technique which resulted in satisfactory differentiation of T and B lymphocytes and monocytes which have migrated as a monolayer for 1-3 days. The Wright-Giemsa staining used in the original method did not permit identification of individual migrating cell types. The most important modifications were changing from a plastic to a glass migration surface, and significantly reducing the overlying thickness of agarose which permitted a short fixation time and easy preparation of permanent slides stained for nonspecific esterase. The esterase staining of monocyte cytoplasm was intense and diffuse. One or two small, discrete areas of cytoplasmic esterase activity were identified in the majority of T lymphocytes. B lymphocytes showed either a trace or no evidence of esterase activity. The modified method should prove useful for the histochemical differentiation of migrating subpopulations of mononuclear cells.