CD45⁺ cells in murine stromal-cell cultures are CD11b⁺ monocytes/macrophages by 2-color flow cytometry analysis. Mouse BM adherent cells were labeled with PE-conjugated anti-CD45 antibody and FITC-conjugated anti-CD3 (A), anti-CD11b (B), or anti-CD19 (C). CD45⁺ cells were predominately CD11b⁺ monocytes/macrophages and negative for T- and B-cell markers (CD3 and CD19, respectively). Numbers represent the percentage of cells in each quadrant.