For quantitative determination of xanthine oxidase enzyme activity and evaluation of its modulators. Key Features: Sensitive and accurate. Use as little as 10 µ L samples. Linear detection range in 96-well plate for 20 minute incubation: 0.03 to 25 U/L xanthine oxidase for colorimetric assays and 0.01 to 2.5 U/L for fluorimetric assays. Simple and high-throughput. The procedure involves addition of a single working reagent and incubation for 20 min at room temperature. Method: OD570nm, FL530/585nm. Samples: Cell lysate, serum, and other biological samples. Species: All. Procedure: Assay takes 20 min. Kit size: 100 tests. Detection limit: FL 0.01 U/L; OD 0.03 U/L.