Hydrogen peroxide commercial kits

More than 90% of commercially available enzyme-based biosensors and analytical kits contain oxidases as terminal enzymes responsible for generation of analytical signal. These enzymes catalyze oxidation of specific analyte with molecular oxygen producing hydrogen peroxide according to the reaction ... 

ALTERNATE PROTOCOL 2 ENZYMATIC MEASUREMENT OF CHOLESTEROL Test combination kits for enzymatic determination of cholesterol in food are now commercially available. For the determination of total cholesterol, esterified cholesterol is hydrolyzed to free cholesterol and fatty acid under mild alkaline conditions. Cholesterol oxidase oxidizes free cholesterol to cholest-4-en-3-one to generate hydrogen peroxide, which further oxidizes methanol to formaldehyde. Formaldehyde then reacts with acetyl acetone in the presence of NH4+ ions to form yellow lutidine dye, which is subsequently determined spectrophotometric al 1 y. 

Chemiluminescence of oxidized luminol has been the basis of several lumino-metric methods of estimation of TAC (Table 1). The mostcommon is to measure the induction time of the reaction. Often the chemiluminescence is first induced by an oxidant and then attenuated by addition of a sample, and the time to recover the initial fluorescence is measured. The enhanced chemiluminescent assay introduced a decade ago is based on the oxidation of luminol by perborate or by hydrogen peroxide in a reaction catalyzed by horseradish peroxidase. Enhancement (and stabilization) of luminescence is achieved by addition of p-iodophenol. The original procedure used a commercial reagent kit (ECL Anti-oxidant Detection Pack... 

Most EIA use HRP as the marker enzyme. The activity of HRP can be measured photometrically as well as electrochemically. Using the catalase activity of liver tissue, Mascini and Palleschi (1983b) developed a tissue-based electrode for the measurement of hydrogen peroxide and combined the sensor with commercial test kits for digoxin and insulin. The HRP-labeled hormones of the test kit compete with antigen in the sample in a test tube. The bound HRP activity is inversely proportional to the concentration of insulin and digoxine, respectively. 

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