BALB/c splenocytes were double-stained with Thy1 monoclonal antibody, clone 30-H12 (APC) (Cat # MAB5958) and Cd19 monoclonal antibody, clone 6D5 (PE) (Cat # MAB5689). Small lymphocytes were then gated and analyzed on a FACScan™ flow cytometer (BDIS, San Jose, CA).