Staged differentiation of hematopoietic progenitors from hESCs. (A) Schematic for the 3-stage hematopoietic differentiation protocol of hESCs. (B) Gene expression changes of EB cells at different stages of development were analyzed by reverse transcription PCR. (C) Development of CFCs during hematopoietic differentiation. (D) Photographs of different hematopoietic colony types derived from stage-3 EB cells. CFU-E indicates erythroid CFU; BFU-E, erythroid burst-forming unit; CFU-GEMM, granulocyte/erythroid/macrophage/megakaryocyte CFU. Images were captured under culture mediums of the cells. The image of CFU-E is shown at 40× original magnification, and the other images are shown at 100× original magnification. Images were recorded with NIS-Elements F 2.30 in the Nikon ECLIPSE TE2000-U microscope system and processed with the Adobe Photoshop CS software. Scale bar, 200 μm. Error bars indicate mean ± SEM (n = 3).