Classification of perivascular and hematopoietic populations for analytical flow cytometry. Stromal vascular fraction (SVF) of adipose tissue from the control, obese and postbariatric surgery ex-obese patients were analyzed by flow cytometry. The viable cells identified by 7-actinomycin D (7AAD) exclusion (A) were first analyzed according to CD45 expression (E, I, M). The gates were set on nonhematopoietic (CD45neg; NHe) and hematopoietic (CD45pos; He) cells. The CD45neg cells (red) were further analyzed for CD34 and CD31 expression (F, J, N) or CD34 and CD146 expression (G, K, O). A green gate was set to identify the subset of supra-adventitial cells (SA), which were CD34posCD31neg, whereas the endothelial progenitor cells (EP) were identified as CD34posCD31pos (purple gate). A blue gate was set on the CD146posCD34neg cells to identify the pericytes. The mono-macrophage cells were analyzed among the He cells (H, L, P). Adipose tissue resident macrophages were identified as CD14posCD206pos cells (upper right quadrant). A population of CD14posCD206neg was also identified (lower right quadrant). (B, C, D) Compensation controls of fluorescence detection. Ctr, control; EP, endothelial progenitor cell; ExOB, postbariatric surgery ex-obese; FITC, fluorescein isothiocyanate; M1rich, enriched in M1 (classically activated) macrophages; M2, alternatively activated macrophages; OB, obese; PC, pericytes; PE, phycoerythrin; PECy5, PE-cyanin 5; SA, supra-adventitial cells.