1X10^6 unstimulated or PMA and Ionomycin stimulated (in the presence of Brefeldin A) C57BL/6 mouse splenocytes were surface stained with CoraLite® Plus 647 Anti-Mouse CD3 (CL647-65077, Clone: 17A2) and then fixed with 4% PFA and permeabilized with Flow Cytometry Perm Buffer (PF00011-C). Cells were then stained with 0.5 ug PE Anti-Mouse IFN gamma (PE-65153, Clone: XMG1.2).