Phenotype and morphology of undifferentiated hES cells and hES cell–derived CD34⁺ cells. (A) Comparative expression of hematopoiesis-associated surface molecules on undifferentiated hES cells (top row) and isolated CD34⁺ cells (bottom row). Depicted histograms represent H1 cells, MFI values in the right histogram corner are mean ± SD of 9 experiments (H1 = 6, H9 = 3). (B) Morphology of Wright-stained cytospins of undifferentiated H1 hES cells. (C) Wright-stained cytospins of isolated H1 CD34⁺ cells demonstrate 2 different populations. (D) Oct-4 immunostaining of undifferentiated H1 ES cells and H1-derived CD34⁺ cells. CD34⁺ cells are Oct-4 negative. Images were captured with an Olympus BX51 microscope (Olympus America Inc.) using 20 × with numerical aperture 0.5 (D) and 100 × with numerical aperture 1.30 (B,C) objectives; and acquired through Spot RT camera and Spot software (Diagnostic Instruments).