Chondrogenic differentiation results of USCs and ASCs in the pellet culture system. Detection of polysaccharide extracellular matrix by toluidin blue staining (a: USCs; b: ASCs). After 4 weeks of induction, both USCs and ASCs formed a shiny surface (USCs: a′; ASCs: b′). The pellets in USC group were further stained with hematoxylin and eosin (H&E) (c, d), Masson trichrome (e, f), and Safranin-O/fast green staining (g). Immunofluorescence detected chondrogenic-related proteins Sox9 and collagen II (h, i). Color images available online at www.liebertpub.com/tea