Fig. 6

Evaluation of chondrogenic differentiation of ASCs. ASCs harvested from retroperitoneal (RP), subcutaneous (SC), and lipoma (LP) fat sources were cultivated as pellets in the presence of chondrogenic differentiation medium (CDM) for up to 21 day. The cell pellets were fixed in 4% PFA and were processed for histological examination. 5-μm sections from all experimental groups were stained using 1% Alcian blue. Photomicrographs of the cell pellet section at day 7 (d–f) and day 14 (g–i) show cartilage glycosaminoglycans (blue) indicative for chondrogenic differentiation. Sections of cells cultivated in basal medium were served as negative controls (BM/NC a–c). j–l Expression fold change of Aggre (j), COMP (k), and Col2a1 (l) at days 7 and 14 post chondrogenic differentiation induction show upregulation of chondrogenic markers in RP and SC derived cells compared to LP cells. The expression was normalized to non-induced cells in BM using 2^−∆∆cq method [30]. All data presented as mean ± SEM. **p < 0.01 and ***p < 0.001. Scale bar = 100 μm