RT-PCR analysis of sorted hESC-derived cell populations. (A) hESCs differentiated for 10 days were sorted for (lane 1) CD34^brightCD31⁺Flk1⁺, (lane 2) CD34⁺CD31⁻Flk1⁺, and (lane 3) CD34⁻CD31⁻Flk1⁻ cells and analyzed for expression of hematopoietic and endothelial transcripts. Human umbilical vein endothelial cells (H) and K562 cells (K) were used as positive controls. (B) Q-RT-PCR analysis for expression of C-MYB from sorted populations: column 1 = CD34^brightCD31⁺Flk1⁺, column 2 = CD34⁺CD31⁻Flk1⁺, and column 3 = CD34⁻CD31⁻Flk1⁻ cells. All samples were normalized to GAPDH expression and compared with C-MYB expression in undifferentiated hESCs. Error bars indicate plus or minus SEM; ***P < .001.