BALB/c splenocytes were double-stained with Tcrb monoclonal antibody, clone H57-597 (FITC) (Cat # MAB5763) and Cd19 monoclonal antibody, clone 6D5 (PE) (Cat # MAB5689), gated on small lymphocytes and analyzed on a FACScan™ flow cytometer (BDIS, San Jose, CA).