FIGURE 1.

Assessment of the purity of nuclear and mitochondrial fractions using Western blotting methodology. Nuclear (N), mitochondrial (M), and cytosolic (C) fractions were prepared from skeletal muscle (quadriceps femoris) of wild-type mice. Histone H2B (A) and VDAC protein (B) content were measured in the nuclear and mitochondrial fractions as an indicator of purity of isolated fractions. C, SOD2 (superoxide dismutase 2, a mitochondrial matrix protein) protein content was measured in nuclear, mitochondrial, and cytosolic fractions to ensure no significant nonspecific leakage of mitochondrial content in nuclear and cytosolic fractions. Histone H2B and VDAC were only detected in nuclear and mitochondrial fractions, respectively, confirming the purity of our fractions. There was no superoxide dismutase 2 detected in both the nuclear and cytosolic fractions.