| 摘要 |
An enzymatic assay and a kit to detect rapidly beta lactam antibiotics in a liquid sample such as milk are shown. In the assay a reaction medium is formed by adding a liquid sample (e.g. raw milk) to a predetermined amount of a combination of dry reagents comprising D,D-carboxypetidase, a substrate for D,D-carboxypeptidase containing a carboxy terminal D-alanine, and a reagent system which produces a color reaction in the presence of D-alanine. Second, the reaction medium is incubated at a temperature between 20 DEG to 60 DEG C for a predetermined period of time. Thereafter a material which quenches the color forming reaction is added and the color of the reaction medium is examined. That color can be correlated to the color intensity found with known amounts of antibiotic. The preferred reagent system which results in a color reaction in the presence of D-alanine comprises a D-amino acid oxidase, a cofactor for D-amino acid oxidase, perioxidase and an organic redox indicator, e.g. odianisidine, which undergoes a color change when oxidized. |
