Research Paper Volume 9, Issue 11 pp 2436—2452

Figure 1. Gating strategies for identifying T-cells that are CD4⁺ (defined as CD4⁺CD8^-) or CD8⁺ (defined as CD4^-CD8⁺). (A) Singlet leukocytes were identified using forward scatter height vs. area scatter on a combined contour and density plot. (B) Lymphocytes were identified using forward scatter area vs. side scatter area on a combined contour and density plot. (C) CD4⁺ and CD4^- lymphocytes were identified with the help of negative isotype controls (set at 1% to distinguish fluorescence signal from non-specific background signals). (D) CD4⁺ and CD4^- lymphocytes were identified with the help of negative isotype controls (set at 1% to distinguish fluorescence signal from non-specific background signals). Using logical Boolean sequences, we distinguished two T-cell populations for further analyses: CD4⁺ T-cells that were CD4⁺CD8^- and CD8⁺ T-cells that were CD4^-CD8⁺.