Fig. 1.

Characterization of mouse skeletal muscle fractions. Mouse hindlimb muscles were excised and fractionated based upon a protocol of density-dependent separation. Protein concentrations of lysate (L), pellet 1 (P1), P2, and cytosol (C) were determined, equal protein amounts of these, as well as equal volume amounts of fractions 1–8 (F1–F8), were resolved by SDS-PAGE, and membranes were immunoblotted using antibodies specific for subcellular protein markers. These protein markers included transferrin receptor (TfR), glucose transporters 1 and 4 (GLUT1 and GLUT4, respectively), dihydroxypyridine receptor α-1 (DHPRα1), cytosolic fatty acid binding protein (FABPc), triadin/trisk95, and β-subunit of F₁-ATPase (F₁ATPase-β). Images of immunoblots are shown.