Chondrogenic ATDC5 and miR-92a expression. Chondrogenic ATDC5 cells were induced with ITS+ Premix, fixed with formalin and stained with alcian blue. (A) ATDC5 without ITS+ Premix exhibited low levels of alcian blue staining. (B) Chondrogenic ATDC5 cells exhibited more marked staining. (C) Expression levels of miR-92a, col2a1 and col10a1 in chondrogenic ATDC5 cells, examined using reverse transcription-quantitative polymerase chain reaction, compared with the negative control of ATDC5 without ITS+ Premix. Error bars indicate the mean ± standard deviation. *P<0.05. miR-92a, microRNA-92a.