METHODS AND KITS FOR QUANTIFYING METABOLITES OR ANALYTES

摘要

Methods and kits for quantifying the amount of a metabolite, such as homocysteine, methionine or cysteine, in a sample are disclosed. This involves contacting the sample with a first enzyme capable of degrading a metabolite into a plurality of reaction products and regenerating the metabolite using a second enzyme which is capable of converting at least one of said reaction product(s), together with an additional substrate or substrates, into said metabolite. This process optionally generates an additional by-product or by-products. After repeating this process, the metabolite is quantified by detecting a level of a reaction product formed by enzyme degradation of said metabolite by said first enzyme, wherein the reaction product is different from the reaction product used in regenerating said metabolite, or detecting a level of said optional by-product produced by said second enzyme or detecting a level of an additional substrate. The method may also involve the initial conversion of an analyte in a sample to a metabolite by contacting the analyte with a reducing agent. The present method further provides a method of quantifying the amount of an analyte in sample by reacting the analyte to produce a metabolite in a cyclic reaction.