Patent ID: 7300769

Claim:
A method for determining the activity of lactate dehydrogenase (LDH) in a sample comprising: (a) providing a first reagent comprising a hydrogen-transferring substrate for the LDH: (b) providing a second reagent comprising a hydrogen-accepting coenzyme selected from the group consisting of NAD, NADP and derivatives thereof, and one or more compounds selected from the group consisting of citric acid or a citrate salt and nitrogen compounds of the formula in which R 1 , R 2 and R 3 are the same or different and denote hydrogen or a saturated or unsaturated alkyl or aryl group; (c) forming a reaction mixture by combining the sample with the first reagent and the second reagent, and (d) detecting the change in absorbance of the coenzyme as a measure of the activity of the LDH present in the sample.