For quantitative determination of glutathione S-transferase activity and evaluation of drug modulators. Key Features: Fast and sensitive. Linear detection range (20 µ L sample) : 2 to 80 U/L for 10 min reaction at 25° C. Convenient and high-throughput. Homogeneous "mix-incubate-measure" type assay. Can be readily automated on HTS liquid handling systems for processing thousands of samples per day. Method: OD340nm. Samples: Biological samples (e.g. cell lysates, tissues, etc.) . Species: All. Procedure: Assay takes 10 min. Kit size: 100 tests. Detection limit: 2 U/L.