Simultaneous spectrophotometric determination of oxidized and reduced glutathione in human and rabbit red cells

An improved spectrophotometric procedure for oxidized and reduced glutathione determination in erythrocytes is described. The method is based upon a reaction using Ellman's reagent. It gave recoveries of 99 and 90% for both GSH and GSSG. The use of oxidized glutathione as an internal standard makes it accurate for simultaneous assay. The method offers the advantage of not having to use alkylation products to prevent oxidation of GSH during protein precipitation. Data are presented to demonstrate reliability and simplicity of rapid estimation of GSH and GSSG.