Characterization of ESC-derived immortalized myeloid progenitors. (A) Wright-Giemsa staining of mEB8-ER (left) or mBB8-ER (right) cells. Bar represents 10 μm. (B) Surface expression of Sca-1, c-Kit, CD45, and CD41 in mEB8-ER and mBB8-ER cells assessed with flow cytometry. Nonspecific IgG was used as a negative control (denoted as “No staining”). (C) Analysis of EB8-ER cells using the CFU assay. Phase-contrast images of cells with (left) or without (right) β-estradiol treatment. (D) The relative percentage of GM, G, and M colonies formed from mEB8-ER cells in the absence of β-estradiol. Quantification of 4 separate experiments. Each represents the mean ± SEM (error bars). (C-D) Cells were cultivated in MethoCult GF M3434 medium for 10 days. Bar represents 50 μm.