Isolated human neutrophils were incubated with 1.0 g anti-human CXCR2 followed by staining with goat F(ab')2 anti-mouse IgG FITC [shaded peak]. Specificity of signal was confirmed by staining the neutrophils with 1.0 g mouse IgG1 isotype control followed by the secondary antibody [unshaded peak]. The data indicate that approximately 98% of the isolated neutrophil population stains positive for this IL-8 receptor (M2 region).