Fig. 3. Serum-deprivation induces myogenic differentiation of C2C12 cells. MyoD and myogenin protein levels were analyzed by western blotting either in C2C12 cells maintained in DMEM containing 10% FCS (growth condition), or 24 hours and 48 hours after switching cultures to DMEM supplemented with 1% HS (differentiation condition). Protein loading was controlled by staining blots with anti-β-actin antibodies. MyoD and myogenin protein levels gradually increased after switching cultures to differentiation conditions.