blood glutathione level serum glutathione level 2014-06-05T12:17:47Z CMO:0002433 JSmith The amount of glutathione in a specified sample of serum, the clear liquid that separates from blood after it has clotted completely, i.e. blood plasma from which fibrinogen has been removed. Glutathione (GSH) is an antioxidant tripeptide with a gamma peptide linkage between the amine group of cysteine (which is attached by normal peptide linkage to a glycine) and the carboxyl group of the glutamate side-chain. clinical_measurement_ontology serum GSH level serum reduced glutathione level