Native rates of superoxide production from multiple sites in isolated mitochondria measured using endogenous reporters

► The redox state of endogenous reporters was calibrated to rates of H2O2/O2− production. ► NADH and cytochrome b reported H2O2/O2− production from complexes I and III. ► Site-specific rates of H2O2/O2− production were quantified under native conditions. ► This approach can quantify site-specific H2O2/O2− production in complex situations.