Skeletal muscle differentiation of AM-hMSCs. RT-PCR for skeletal muscle transcription factors MyoD and Myogenin. MyoD appears after 1 week of induction while Myogenin is expressed in the second week of induction. Samples are as follows: lane 1: AM-hMSCs cultured in control medium; lane 2: induced AM-hMSCs after 7 days; lane 3: induced AM-hMSCs after 14 days; lane 4: positive control (RD18 cell line); lane 5: reagent control. Beta-actin was used as a house-keeping gene (A). Immunocytochemical staining for Desmin after 3 weeks' induction: uninduced AM-hMSCs (B) and Desmin positive induced cells (C).