Fig. 3. Proliferation potential of BMSSC clones. A total of 35 CFU-F colonies derived from STRO-1^BRIGHT/VCAM-1⁺ single sorted cells from two BM samples were analysed for their cumulative production of cells. A marked variation in proliferative capacity between individual BMSSCs is evident. The majority of clones (29/35, 83%) exhibited only moderate growth potential, which did not persist beyond 20 population doublings. 6/35 clones (17%) demonstrated continued growth extending beyond 20 population doublings.