Normal human peripheral blood cells were stained with CD19 Monoclonal Antibody, FITC (Product # 11-0199-42) and staining buffer (autofluorescence) (left) or 1.0 µg of Mouse IgG2b kappa Isotype Control, Brilliant Violet 480 (Product # 414-4732-81) (right). Viable cells in the lymphocyte gate were used for analysis, as determined by 7-AAD (Product # 00-6993-50).