描述:MitoB is a ratiometric mass spectrometry probe that can be used for assessing changes in H2O2 within mitochondria in vivo. MitoB contains a triphenylphosphonium cation component that drives its accumulation in mitochondria where its arylboronic moiety selectively reacts with H2O2 to produce a phenol product, MitoP.1,2 Quantifying the MitoP/MitoB ratio by LC-MS/MS reflects the mitochondrial matrix H2O2 concentration.