MSCs were isolated from bone marrow at high purity. Cells expressing CD90. 1 and CD29 were identified using fluorescence-activated cell sorting. Cells consisted of a heterogeneous cell population with a predominant spindle morphology. Cells cultured for three days (A) and one (B), two (C), and three weeks (D) were photographed, and MSCs proliferated to form a small colony on day 3. A large colony of densely distributed spindle- and triangle-shaped MSCs formed after three weeks.

Figure 1: Phase-contrast micrographs of MSCs at three days and one, two, and three weeks of primary culture.