Rapid method for determining T lymphocyte levels using acid alpha-naphthyl acetate esterase.

A method for rapidly determining levels of T lymphocytes in humans is presented. The method involves staining lymphocytes in peripheral blood or buffy coat smears for acid alpha-naphthylacetate esterase for 1 hr at 37 C. After counterstaining with Wright's stain, the percentage of esterase-positive lymphocytes accurately reflects the percentage of lymphocytes forming E rosettes with sheep erythrocytes.