Immunofluorescence labeling of CXCR4 and CCR5 in normal monocytes and neutrophilic granulocytes isolated from PB. (A and D) Staining using matched control antibodies. Monocytes were stained with either PE-conjugated CXCR4 (B) or CCR5 (C) MoAb along with CD14-FITC MoAb; neutrophils were labeled with either PE-conjugated CXCR4 (E) or CCR5 (F) MoAb along with CD15-FITC MoAb.