Mitochondrial extracts from control 143B cells (left), COX1∆ cybrids (right), and COX2∆ cybrids (middle) were immunoprecipitated using antibodies against: (C) CIII subunit CORE2. Samples were subsequently analyzed by SDS-PAGE and immunoblotting with the indicated antibodies. In, input. IP, immuno-precipitate. FT, flow-through. Ig, unrelated immunoglobulin used as a negative control. 