1x10^6 unstimulated or anti-CD3/CD28 stimulated (2 days) mouse splenocytes were surface stained with 0.5 ug Anti-Mouse CD274 (PD-L1, B7-H1) (65073-1-Ig, Clone:10F.9G2) and FITC-anti Rat IgG2b at dilution 1:100 and 0.5 ug CoraLite® Plus 647 Anti-Mouse CD3 (17A2) (CL647-65077, Clone: 17A2). Cells were not fixed.