Evaluation of sorting efficiency.

<p>TC71 cells were incubated with the Aldefluor reagent and sorted as described (A). Viable (based on PI exclusion) ALDH^low and ALDH^high cells were isolated as indicated by the arrows (B). The viable cells from each population (as well as the entire population, in the center panel) were analyzed for Aldefluor-related fluorescence (C), and an overlay of the resulting histograms shows no appreciable overlap (D), demonstrating a sorting efficiency of >98%. This check was performed three times, and the data presented are from a representative experiment.