MitoCDNB is a mitochondrially selective inactivator of mitochondrial thiol redox homeostasis in isolated cells and in vivo. MitoCDNB selectively depletes the mitochondrial reduced glutathione (GSH) pool by formation of MitoGSDNB and dramatically increasing absorbance at 328 nm. It directly inhibits mitochondrial thioredoxin TrxR2 and peroxiredoxin 3.