Hematopoietic differentiation of ES cells. (A) Schematic showing the 2 ES cell differentiation protocols used in this study. ES cells were placed in a 3-phase coculture differentiation system or an embryoid body differentiation system. For a full description, see “Materials and methods.” (B) Examples of the hematopoietic colony types obtained in this study, original magnification ×100. A 10×/0.4 objective lens was used.