Surface staining of human PBMC with anti-human CD25 FITC (Clone MEM-181, SM3015F).The mononuclear cells were isolated from human peripheral blood, devided in aliquots for duplicate analysis and stim ulated with PHA for 2 days. Panel A, C ?? staining with anti-human CD25 (Clone MEM-181)Panel B, D ?? staining with a standard anti-CD25 monoclonal antibody