Fig. 6

Evaluation of adipogenic differentiation by Oil Red O staining. Lipid droplets (stained in red) and the more rounded cell morphology are representative of successful adipogenic differentiation. Representative images of every donor were obtained using the phase contrast setting of an Olympus IX51 inverted microscope. The negative controls received expansion medium for 21 days. The scale bar is set at 100 µm. The donor numbers of clinically normal (N) and OA (O) donors correspond to the donor numbers and information in Additional file 1: Table S1. B Gene expression of the osteogenic markers adiponectin (ADIPOQ) and peroxisome proliferator-activated receptor gamma (PPARG) is shown as the N-fold change of the cells treated with osteogenic differentiation medium compared to their own negative control. Each dot represents an individual donor. *p < 0.05