Figure 1
Gating strategy for the volumetric Auto40 flow cytometer (Apogee Flow Systems Ltd, Hemel Hempstead, UK), as depicted from typical figure provided by “Auto-Lymphocyte” software (Apogee Flow Systems Ltd) for the counting of CD4 T lymphocytes in one K 3 -EDTA-anticoagulated blood sample, incubated with phycoerythrin (PE)-conjugated anti-CD4 and PE-Dyomics649-conjugated anti-CD45 monoclonal antibodies (Apogee Flow Systems Ltd): (A) CD45-PE-Dyomics649 × axis-light scatter dot plot scattergram; the primary CD45 gating differentiates clearly the CD45-positive lymphocytes and monocyte populations, and the population of polymorphonuclear cells; (B) CD4-PE × axis-light scatter dot plot scattergram; double secondary CD4 gating allows counting independently the population of CD4-negative lymphocyte and CD4-positive lymphocytes; the CD4 T lymphocytes count in absolute number is given by the CD4-positive gating; the CD4 T lymphocytes count in percentage corresponds to the ratio of CD4-positive lymphocytes count in absolute number to the total CD4-postive and CD4-negative lymphocytes counts, corresponding to the sum of both secondary gating.