Glutathione S-transferases Assay

Glutathione S-transferases (GST) comprise a family of enzymes that plays an important role in cellular detoxification of xenobiotics. GST catalyzes the conjugation of reduced glutathione to electrophilic xenobiotics and utilizes reduced glutathione to scavenge potentially toxic compounds. GST activity measurement has been used as biomarker for diagnoses of tumor and liver damage and oxidative stress. This colorimetric assay is based on the GST-catalyzed reaction between reduced glutathione and GST substrate, 1-chloro-2, 4-dinitrobenzene (CDNB). The GST activity is determined by measuring the rate of produced conjugation between reduced glutathione and CDNB, which is proportional to the increase in absorbance at 340nm over time (ΔOD_340nm/min).