Subpopulations of human peripheral blood cells: Analysis of granulocytic progenitor cells by flow cytometry and immunologic surface markers

Normal human peripheral blood cells were separated into different populations based upon isopycnic sedimentation, E rosetting, and EAC rosetting. Each population was characterized according to morphology, surface markers, granulocytic colony formation in semi‐solid media, and stainable RNA content by acridine orange (AO) flow cytometry. These techniques enrich for a population of cells that is characterized by a lymphoid morphology, a high granulocytic‐macrophage progenitor cell cloning efficiency, a lack of surface markers, and a high stainable RNA content not found in the other two populations of peripheral blood lymphocytes (T cells and B cells). The stainable RNA content serves as a new metabolic marker for the population of cells in which the preponderance of granulocytic progenitor cells reside.