FACS analysis of CD16b antibody binding to isolated human blood eutrophils. A. Histograms of relative cell count for Isotype control (irrelevant, species-matched IgG antibody), and CD16b antibody (mouse anti-human IgMκ; 1D3 clone) for Control (no additions), PAF alone (10-9M), feG alone (10-11M) and feG in the presence of PAF. PAF only modestly increases fluorescence intensity relative to Control, and feG decreases the fluorescence intensity below those seen in Control. Histograms are representative tracings. B. Dot plot of cell sample treated with 10-9M PAF showing homogenous nature of the isolated neutrophils. The dot plot is representative of cell samples for Control and feG treated cells.