Simple and rapid measurement of human T lymphocytes and their subclasses in peripheral blood

A simple and rapid method for the determination of human T lymphocyte subclasses in buffy coat preparations or whole blood is described. This technique uses flow cytometry to distinguish lymphocytes from other leukocytes on the basis of their light-scattering properties. Lymnphocyte subclasses were enumerated by cellular immunofluorescence; the immunofluorescent signals were produced by monoclonal antibodies to surface differentiation antigens on T cells. Conventional techniques of enumerating T lymphocyte subclasses entail time-consuming (up to 2 days) density gradient and E rosette enrichement, and require at least 20 ml of blood. The method described here uses as little as 50 microliters of whole blood for each antibody tested and produces results within in 2 hr.