C57Bl/6 splenocytes were unstimulated (left) or stimulated (right) with F (ab')2 Anti-Mouse IgM, u chain specific Functional Grade Purified (Product # 16-5890) and Anti-Mouse CD40 Functional Grade Purified (Product # 16-0401-82) for 3 days and then stained with Anti-Mouse CD19 FITC (Product # 11-0193-82) and 0.25 µg of Anti-Human/Mouse GL7 (T and B Cell Activation Marker) PerCP-eFluor® 710. Total viable cells, as determined by Fixable Viability Dye eFluor® 506, were used for analysis.