Figure 1
Human ESC-derived sac-like structure (ES-sac). (A) Schematic diagrams of 2 different in vitro differentiation protocols for human embryonic stem cell (hESC)–derived megakaryocytes and platelets. (i) Megakaryocytes are generated on OP-9 stromal cells, as described previously.16 (ii) Megakaryocytes are generated from the cells within ES-sacs on days 14 to 15. (B) Photomicrographs showing undifferentiated hESCs (day 0) and differentiated stages on C3H10T1/2 cells (days 4, 7, and 14). On day 14, ES-sacs appeared. Original magnification, 40×. A high-magnification view (day 14) shows an ES-sac containing numerous bright, spherical cells (200×). VEGF indicates vascular endothelial growth factor; TPO, thrombopoietin.
