Figure 1.

Flow cytometry analysis of ALDH^hi atrial cells. (A) Freshly isolated cells. ALDH^hi gating was established by inhibiting ALDH activity in Aldefluor-reacted cells with DEAB. Left panels: ALDH/side scatter (SSC-A) plots. Right panels: ALDH/forward scatter (FSC-A) plots. (B) Freshly isolated cells. Aldefluor activity and CD34 expression. (C) CD34 immunostaining (red); ALDH (green); staining with istotype-matched control antibody is shown. (D) ALDH^hi cells (%) did not correlate with age. (E) FACS plots of different populations (top to bottom: freshly isolated atrial cells, freshly isolated LV cells, expanded atrial cells, atrial outgrowth cells). Gating sequences are shown. R1-gated cells in FSC-A/SSC-A plots are gated for homogeneity (R2, R3) and DAPI exclusion (R4). R5 and R7 gates define ALDH^lo and ALDH^hi cells, respectively. To prevent cross-contamination between ALDH^hi and ALDH^hi cells, R5 and R7 gates were set one log apart (i.e., R6-gated cells were discarded). (F) Percentages of ALDH^hi outgrowth cells after 1–4 weeks of ex vivo tissue culture.