Electrophoresis techniques to investigate defects in oxidative phosphorylation

Defects in mitochondrial oxidative phosphorylation (OXPHOS) are a frequent cause of severe inherited metabolic disorders and also contribute to aging. The OXPHOS system constitutes five multi-subunit complexes embedded in the mitochondrial inner membrane. Correct function of this system requires proper assembly of the ∼80 proteins in the complexes, as well as numerous assembly factors. Blue native electrophoresis has become a crucial tool to investigate OXPHOS-related defects in mitochondrial disease patients. In addition, OXPHOS-assembly profiles can be obtained by two dimensional blue native/SDS gel electrophoresis, which provides additional information for identifying disease-causing mutations and insight in the role of specific proteins in the biogenesis of the OXPHOS system. Here we provide a practical guide on how to set-up the basic technique to study OXPHOS defects in patient-derived cells and tissues.