IBTP is a lipophilic cation that is accumulated in mitochondria and forms stable thioether adducts in a thiol-specific manner. As a result, mitochondrial proteins that have changed thiol redox state following oxidative stress are selectively tagged with IBTP and can be separated by two-dimensional electrophoresis and isolated. IBTP-tagged proteins can also be evaluated by immunoblotting using an antibody directed against the triphenylphosphonium moiety of the IBTP molecule. IBTP has also been used as a mitochondria-targeted soft electrophile to inhibit mitochondrial oxidative phosphorylation.