Western Blot analysis of fibroblasts. Western blot analysis of collagen VI in cultured skin fibroblasts and in muscle biopsies from control (CTRL) and BM Patient 1 (BM1) was performed. Samples corresponding to the cell layer (left panel, 20 μg) and medium (middle panel, 30 μg) in the presence or absence of L-ascorbate, and muscle extracts (right panel, 15 μg), were separated by electrophoresis under reducing conditions in 3-8% polyacrylamide-gradient gel. Collagen VI was detected by immunoblotting with antibodies recognizing either all collagen VI chains (Fitzgerald 70XR95) or the α1(VI) chain (Santa Cruz sc-20649). Migration of the collagen VI chains is indicated on the right and molecular weight markers (kDa) are shown on the left. Control for loading was performed by antibodies against AKT (cell layers) or myosin (muscle biopsies).