2 mg of purified rat liver mitochondrial membranes resuspended in 400 µl of heart mitochondria resuspension buffer (10 mM Tris.HCl, pH 7.8, 0.2 M sucrose, 0.2 mM EDTA, 1 mM PMSF). 1 mg solubilized mitochondria for Immunocapture experiments. For the Immunocapture of OXPHOS complexes it is recommended that 180 µl of the mitochondrial membranes supplied be solubilized by the addition of 20 µl of 10% lauryl maltoside. Insoluble material is removed by centrifugation at 72,000g before immunocapture of complexes from the supernatant.