HSCs of lower mitochondrial activity maintain higher ex vivo stem cell function. (A) Gating strategy for FACS sorting MMP-low or MMP-high (25% lowest and highest of parental population, applied throughout the entire article except Figure 1 or otherwise indicated) CD38⁻ HSPCs or CD90⁺ HSCs. (B,D) Representative scatter plots of limiting dilution analysis of LTC-IC frequency in MMP-low or MMP-high PB (B) CD90⁺ HSCs or (D) CD38⁻ HSPCs. Dotted lines indicate LTC-IC frequency determined by Ln 37% nonresponder. P values calculated using L-Calc software, **P < .01, (C,E) Total number of LTC-IC–derived CFC generated from 150 initially seeded MMP-low and MMP-high PB (C) CD90⁺ HSCs or (E) CD38⁻ HSPCs; (n = 2). Data are represented as mean ± standard deviation; (C,E) Student t test, *P < .05, **P < .01.