Positive selection of mouse B and T lymphocytes and analysis of isolated populations by flow cytometry.

Mouse spleen cells were separated into Ig+ and Ig- populations by positive selection using petri plates coated with rabbit anti-mouse immunoglobulin. The Ig- cells were subsequently incubated with mouse monoclonal alloantisera to Thy1.2 prior to a second positive selection. The adherent populations were characterized as B (Ig+) or T (Thy1.2+) lymphocytes on the basis of surface immunofluorescence and mitogen-induced proliferation. Analysis of the 2 isolated populations by flow cytometry showed that B and T lymphocytes could be distinguished by their forward light scatter as well as their fluorescence after incubation with fluorescein diacetate.