C57BL/6 mouse splenocytes were stimulated for 72 hours with Mouse IgM Monoclonal Antibody, Functional Grade (Product # 16-5092-85) and CD40 Monoclonal Antibody, Functional Grade Purified (Product # 16-0401-85). Cells were then stained with 0.5 µg of Rat IgG2b kappa Isotype Control, Alexa Fluor 488 (Product # 53-4031-80) (blue histogram) or 0.5 µg of CD252 Monoclonal Antibody, Alexa Fluor 488 (purple histogram). Total viable cells were used for analysis, as determined by 7-AAD (Product # 00-6993-50).