Lglutathione (GSH) is a tripeptide made of three amino acids (glutamate, cysteine and glycine) and is the body's main intracellular antioxidant. It neutralizes harmful oxygenbased molecules, protects proteins and cellular machinery from Frontiers Exogenous cystine increases susceptibility of drug resistant Salmonella to gentamicin by promoting oxidation of glutathione metabolism and imbalance of intracellular redox levels Real time imaging of the intracellular glutathione redox potential Nature Methods A locally activatable sensor for robust quantification of organellar glutathione Nature Chemistry