Used to measure the activity of γ-glutamylcysteine synthetase (γ-ECS) in human biological samples such as cell lysates, tissue extracts, or serum. This assay is commonly applied in research focused on oxidative stress, glutathione metabolism, and cellular defense mechanisms. It enables researchers to quantify changes in γ-ECS levels under disease conditions like neurodegenerative disorders, liver disease, or cancer, and to evaluate the impact of therapeutic agents on antioxidant pathway regulation. The ELISA format allows for high-throughput, sensitive, and specific detection, making it suitable for both clinical studies and experimental pharmacology.