Figure 4. Identification of ALDH⁺ and ALDH⁻ subpopulations in 1^st and 2^nd generation tumours.

Sorted viable ALDH⁺ and ALDH⁻ cells from the Melmet 1 xenograft were injected s.c (the tumour growth curves are presented in Figure 3A), and the formed 1^st generation tumour were: i) resorted into ALDH^+/+, ALDH^+/−, ALDH^−/− subpopulations that were reinjected for formation of 2^nd generation tumours (the growth curves are presented in Figure 3B); ii) divided into small peaces of tumour tissue that were transplanted for formation of 2^nd generation tumours. All formed tumours were reanalyzed by the Aldefluor assay. The gates were set based on “+DEAB controls” (not shown).