FACS analysis of 32Dcl3 and HL60 cells with the anti–PSGL-1 MoAb 2PH1. 32Dcl3 cells and HL60 cells (as indicated) were analyzed by flow cytometry with MoAb 2PH1 and control antibodies. Binding of 2PH1 to 32Dcl3 cells (A) and to HL60 cells (B). Positive control staining of HL60 cells with the anti–Mac-1 antibody M1/70 is shown as a faint line. (C and D) 32Dcl3 cells were either pretreated with O-sialoglycoprotease (with OSGPase, faint line) or mock-treated (without OSGPase, bold line) and then analyzed for binding of 2PH1 (C) or binding of the anti–PECAM-1 antibody EA3 (D). All dotted lines (Co) show negative control staining with a nonbinding rat IgG.