Rapid Quantification of Oxidized and Reduced Forms of Glutathione Using Ortho phthalaldehyde in Cultured Mammalian Cells In Vitro Rapid and effective protocol to measure glutathione peroxidase activity Bulletin of the National Research Centre Springer Nature Link A rapid colorimetric method for determining glutathione based on the reaction between cobalt oxyhydroxide nanosheets and 3,3,5,5 Tetramethylbenzidine ScienceDirect Cellular Glutathione Detection Assay Kit Cell Signaling Technology