Expression of CD21 and CD11 antigens by SMS-SB cells. Aliquots of SMS-SB and other B-lymphoid cell lines were harvested, washed in PBS, and stained with FITC-conjugated MoAbs specific for the CD11a, CD11b, CD11c, CD18, CD19, and CD21 antigens. After a 30- to 60-minute incubation, the cells were washed, and analyzed by flow cytometry; nonviable cells were excluded from acquisition by propidium iodide counter-staining, and each graph represents the data from 10,000 live-gated events. Line styles are indicated on the individual panels, and “auto” refers to autofluorescence of unstained cells. (A) CD11a expression on SKW and SMS-SB cells. (B) CD11b expression on SKW and SMS-SB cells. (C) CD11c expression on SKW and SMS-SB cells. (D) CD18 and CD19 expression on SMS-SB cells. (E) Expression of CD21 on Daudi, Ramos, and SMS-SB cells.