Figure 2.

Morphology and surface antigen of MSCs. The bone marrow cells were small and round and suspended in culture fluid just after inoculation (A). After 24 h some cells adhering in the flask were visible (B). After plating for 72 h, the attached cells were proliferating and dividing, and the cells showed a spindle or polygonal shape (C). After about 10 days, the cells reached 80% confluence before being subcultured (D). After 3-4 passages, the cells presented a relatively homogeneous spindle shape (E), and were arranged in parallel or spiral (F). Cells were positive for CD44 (G) and negative for CD34 (H). Scale bar: (A-D) = 100 μm; (E-H) = 50 μm.