High sensitive assay method of L-carnitine and composition for an assay.

摘要

A method of assaying L-carnitine which comprises reacting a specimen comprising the L-carnitine to be assayed with reagents comprising: 1/ &cir& L-carnitine dehydrogenase which has coenzymes of the thionicotinamide adenine dinucleotide group (hereinafter designated as the thio-NAD-group) and nicotinamide adenine dinucleotide group (hereinafter designated as the NAD group) and which catalyses a reversible reaction forming essentially dehydrocarnitine from L-carnitine; 2/ &cir& A1; and 3/ &cir& B1; to perform the cycling reaction: wherein: A1 is the thio-NAD group or the NAD group; A2 is a reduced form of A1; when A1 is the thio-NAD group, B1 is a reduced NAD group and when A1 is the NAD group, B1 is a reduced thio-NAD group, and B2 is an oxidized form of B1; and measuring the amount of A2 generated or B1 consumed.