Surface staining for CD3+CD4+CD25high T cells. Ex-vivo thawed PBMCs were stained for immunophenotyping of T cells Subsets with a crucial role in immune response modulation. a) Lymphocytes were gated based on their light scatter characteristics in both ethnic groups. b) and c) Unstained cells and isotype control are used for positive events threshold determination in CD25 channel. Then based on fluorescence intensity level, CD25 high subsets were drawn.