Figure 6: Histochemical staining of differentiated stem cells and semiquantification of the extent of cell differentiation. Both AFSCs and NPSCs were able to differentiate into adipocytes stained in red by Oil Red O ((a), (b), and (c), white arrows), osteocytes stained in dark brown by Alizarin Red S ((d), (e), and (f), black arrows), and chondrocytes stained in red by Safranin O ((g), (h), and (i), green arrows) and stained in green by Alcian Blue ((j), (k), and (l), red arrows), as shown by the accumulation of lipid droplets ((a), (b), red areas), calcium deposits ((d), (e), dark brown areas), and proteoglycans ((g), (h), red areas; (j), (k) green areas) on cell surfaces. However, the extent of AFSC differentiation was less than that of NPSC differentiation, evidenced by smaller positive staining areas for adipogenesis (a, c), osteogenesis (d, f), and chondrogenesis (g, i, j, l) in AFSCs than in NPSCs. Bars: 100 μm.