Figure 7. ALDH functional activity in expanded CB CD34⁺ cells.

(A) PCs treated under control conditions or with VPA for 7 days with cytokines were assessed for ALDH activity. Contour plot analyses of various populations of cells including ALDH⁺CD34⁺ cells (left panel) and ALDH⁺ cells (middle panel). ALDH⁺ cells (blue box) were gated for coexpression of CD34 and c-Kit (CD117) (right panel). A greater degree of ALDH activity was observed in SF versus SC control cultures (P = 0.005) as well as in VPA-containing cultures (P = 0.001). Similarly, the percentage of ALDH⁺CD34⁺ and ALDH⁺CD34⁺CD117⁺ cells was significantly greater in SF than in SC cultures (P = 0.001 and P = 0.007, respectively). One of 3 to 5 representative experiments is shown. (B) A far greater number of ALDH⁺CD34⁺CD117⁺ cells was generated in the presence of VPA in SF cultures as compared with that in SC cultures (mean ± SEM; *P < 0.05; **P < 0.005; ANOVA, P = 0.009; n = 3–5).