(A) Schematic representation of the optimized differentiation protocol used to generate hematopoietic precursors and progenitors from ESCs. (B–D) Relative expression of Oct4, Brachyury, and Wnt3a, respectively on days 4 and 7. (E) Immunostaining for Oct4, Brachyury, and DAPI (4',6-diamidino-2-phenylindole) during initial differentiation of colonies on days 4 and 7. ^a)P <0.05, ^b)P <0.01.