This High Throughput Glutathione Reductase Assay measures cellular levels of glutathione reductase, an enzyme which catalyzes the reduction of oxidized glutathione (GSSG) to reduced glutathione (GSH). The kit is a spectrophotometric assay provided in a 96 well format for high-throughput screening, and it is suitable for cell lysates, erythrocyte lysates and tissue homogenates.