Analysis of monocyte CD14/CD16 subpopulations in density gradient purified monocytes. Ficoll purified buffy coats from normal blood donors were subjected to a second percoll gradient to enrich for monocytes and analyzed by flow cytometry for CD14/CD16 subpopulations. (Top row): The forward (FSC) and side scatter (SSC) of leukocytes after gradient purification and gating with the isotype controls are shown. (Second row): The CD14 fraction of four different donors plotted against SSC is shown and the percentage of CD14+ monocytes is given. (Bottom row): The CD14/CD16 population of four different donors is shown. The percentage of CD14 + CD16+ monocytes is given and the mean fluorescent intensity is indicated in the top right corner of each panel.