Flow cytometric assessment of endothelial-cell chimerism. The adductor muscle from the ischemic limb was isolated 14 days after induction of hindlimb ischemia, digested with collagenase to generate a single-cell suspension, and then analyzed by flow cytometry. (A) Representative FACS plots of nontransgenic FVB (control) (n = 3) and Tie2GFP (n = 3) transgenic cells showing GFP expression; staining for 7-AAD was used to identify nonviable cells. (B) Expression of CD45 and CD146 (MUC18 antigen) by GFP⁺ cells from Tie2GFP transgenic mice is shown. Isotype controls are shown as dashed lines. (C) Representative histograms from 3 recipient mice in which Tie2GFP blood mononuclear cells had been adoptively transferred. Shown is the percentage of GFP-positive cells.