Flow-cytometric analysis of leukocyte subsets from the peripheral blood of normal individuals. (A) Gating strategy for identifying leukocyte subsets. (B) Mer expression on the surface of leukocyte subsets. MFI represents the mean fluorescence intensity obtained with the anti-Mer antibody. The data are from a group of normal healthy individuals (n = 14). (C) Mer expression varies over time. The expression of Mer on the CD14int population and the CD14++ monocytes was examined in two normal individuals at different time points.