Cells from BALB/c mesenteric lymph nodes were double-stained with Ptprc monoclonal antibody, clone RA3-6B2 (FITC) (Cat # MAB5720) and Cd3e monoclonal antibody, clone C363.29B (FITC) (Cat # MAB6100). Small lymphocytes were then gated and analyzed on a FACScan™ flow cytometer (BDIS, San Jose, CA).