Flow cytometric analysis of unfractionated and density fractionated cells from a day 4 leukapheresis sample from a normal donor given daily G-CSF injections. Panels U and C1-C5 in (A) show the obtuse versus forward light scatter profiles of unfractionated (U) and density fractionated cells (C1-C5). Boxes enclose the “mononuclear/lymphocyte” gate, and the percentages of cells enclosed in the boxes are shown. Panels U and C1-C5 in (B) show the one-color analysis of immunofluorescent staining with PE-conjugated anti-CD34 monoclonal antibodies (open area) compared with background control staining (shaded area). The vertical lines show the staining threshold established from C1, and the percentages of cells staining with anti-CD34 antibodies above the threshold are shown.