Fig. 4

Histological analysis of differentiation. Oil Red O staining was employed to detect lipid accumulation after adipogenic differentiation (top row). All clones examined except clone # 3 demonstrated Oil Red O positive staining. Safranin O staining was employed to detect proteoglycan accumulation after chondrogenic differentiation (middle row). Only clone # 1 demonstrated positive Safranin O staining. Alizarin red staining was employed to detect calcium accumulation after osteogenic differentiation (bottom row). None of the clones examined demonstrated positive Alizarin red staining. A characterized and non-clonal MSC line was used as a positive control (right column) and demonstrated positive staining for Oil Red O, Safranin O and Alizarin Red. Scale bars equal 50 μm for Oil Red O and Alizarin Red stained images, and 200 μm for Safranin O stained images