Differentiated cells in a chemically defined culture of ES cell–derived VEGFR2⁺ cells.

Sorted VEGFR2⁺ cells were cultured on type IV collagen–coated dishes under a chemically defined condition without (A-B) or with (C-F) 50 ng/mL VEGF. After 1 day (A,C), 3 days (B,D), or 2 days (E) of culture, differentiated cells were observed by phase-contrast microscopy. (F) Cells shown in panel E were doubly stained with MoAbs for VE-cadherin (purple) and α-smooth muscle actin (brown). Note that spindle-shaped or dendritic-shaped cells were positive for VE-cadherin or α-smooth muscle actin, respectively. Scale bars = 100 μm.