[A sensitive method for quantitative analysis of hydrogen peroxide and oxidase substrates in biological samples]

The sensitive method for peroxidative assays of hydrogen peroxide (up to 5 nmole in 1 ml) and oxidases' substrates (glucose, ethanol) has been developed by use of a non-cancerogenic chromogen--3,3', 5,5'-tetramethylbenzidine (TMB), horseradish peroxidase and corresponding oxidases. The proposed modification of the known method consists in using decreased concentration of TMB (0.05-0.1 mM) and stopping the reaction by adding of acid to pH 1.4-2.1. This approach allowed to enhance the sensitivity of assays of corresponding analytes (7-10 times) and decrease the costs of analysis.