Fluorometric Xanthine Oxidase Assay Kit

Xanthine oxidase (XO) is an important enzyme in the purine metabolism pathway, which can catalyze the oxidation of hypoxanthine to xanthine, and then further oxidize xanthine to uric acid, and produce hydrogen peroxide (H₂O₂). XO is widely found in a variety of organisms, such as humans, animal livers, intestines, and other tissues. In some disease states, such as liver disease, XO is released from cells into the bloodstream, so the level of XO activity in the blood can be used as a sensitive indicator to assess liver damage. Detection of XO activity is of great significance for studying the pathogenesis of related diseases and monitoring the efficacy of treatment.

Fluorometric Xanthine Oxidase Assay Kit provides an ultra-sensitive method for detecting XO activity. This kit uses Amplex Red as a fluorescent probe, and under the presence of horseradish peroxidase (HRP), Amplex Red can react with H₂O₂, to produce a pink fluorescent substance, Resorufin, whose fluorescence intensity and absorbance are proportional to the XO activity.

Compared with the traditional xanthine oxidase assay kit (WST-8), this kit is more sensitive and more flexible. The kit can be detected by both fluorometric and colorimetric methods, but the sensitivity of fluorescence detection is approximately 10-fold higher than that of colorimetric methods. Therefore, fluorescence detection can be performed with a smaller amount of sample to detect activity, and the kit has a good linearity in the activity range of 0.25-4 mU/mL when used for fluorescence detection.

Figure 1: Xanthine oxidase assay scheme

Figure 2: Reference standard curve for this kit