Flow Cytometry analysis of cell-specific surface molecule expression on peripheral blood and spleen mononuclear cells in C57BL/6 and BALB/c male mice. Shown on the figure are PBMC (A) and spleen (B) mononuclear cells from randomly chosen mice regardless of age. Cells were separated, stained with directly conjugated mAbs to several cell-specific markers and isotype-matching controls, and gated as low FSC and SSC populations. The MHC class II, CD19 and CD3 staining was analyzed by using single histogram statistics (columns 1, 2, 3, respectively). Two-color analysis for the CD4/CD8, CD11b/CD11c staining was performed by using dot plots with quadrant statistics (columns 4 and 5, respectively). Analysis of the CD4/CD44 and CD8/CD44 staining in the spleen was performed by using dot plots with multiple gate statistics (columns 6 and 7, respectively). The numbers (1, 2, 3, 4 on the dot plots in columns 6 and 7 represent the indicated CD4+ (column 6) and CD8+ (column 7) CD44high, CD44med, CD44low, CD44neg T cell sub-populations, respectively. For statistical analysis, as indicated on (B), the CD44high and CD44med sub-populations were combined into CD44med/high (activated/memory) and, similarly, the CD44low and CD44neg sub-populations were combined into CD44neg/low (naïve) T cell populations. (C) To eliminate the contribution of B and T cells to the % of CD11b/c cells, a three-color analysis (CD19, CD11b and CD11c; CD3, CD11b, CD11c; for B- and T-cell, respectively) was performed and analyzed by dot plots with quadrant statistics.