Acid alpha-naphthyl acetate esterase assay in murine lymphocytes.

Acid alpha-naphthyl acetate esterase (ANAE) activity was assayed in cell homogenates and in intact cells by an endpoint colorimetric method, in which sodium dodecyl sulfate was used to stop the reaction. Each method of cell disruption and enzyme solubilization tested here caused a partial loss of the ANAE activity in lymphocyte preparations. The majority of the ANAE activity in lymphocytes was found to be membrane bound. The ANAE activity in thymocytes was over two times lower than that obtained for lymph node and spleen lymphocytes. Macrophages were found to contain about 18 times higher ANAE activity than mature lymphocytes.