Overlay histogram showing PHA-stimulated huuman peripheral blood lymphocytes stained with CD25 antibody (green line). The cells were icubated in 2% bovine serum albumin to block non-specific protein-protein interactions followed by the antibody (1:50 dilution) for 60min at 37°C. The secondary antibody used was Goat Anti-Mouse IgG, DyLight® 488 Conjugated Highly Cross-Adsorbed (OJ192088) at 1/200 dilution for 40min at 37°C. Isotype control antibody (blue line) was mouse IgG2a (1µg/1x10^6 cells) used under the same conditions. Acquisition of >10, 000 events was performed.