Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7233812 | Biosensors and Bioelectronics | 2013 | 6 Pages |
Abstract
Regulatory restrictions on antibiotic residues in dairy products have resulted in the illegal addition of β-lactamase to lower antibiotic levels in milk in China. Here we demonstrate a fast, sensitive and convenient method based on enzyme thermistor (ET) for the surveillance of β-lactamase in milk. A fixed amount of penicillin G, which is a specific substrate of β-lactamase, was incubated with the milk sample, and an aliquot of the mixture was directly injected into the ET system to give a temperature change corresponding to the remained penicillin G. The amount of β-lactamase present in sample was deduced by the penicillin G consumed during incubation. This method was successfully applied to quantify β-lactamase in milk with the linear range of 1.1-20 U mLâ1 and the detection limit of 1.1 U mLâ1. The recoveries ranged from 93% to 105%, with relative standard deviations (RSDs) below 8%. The stability of the column equipped in ET was also studied, and only 5% decrease of activity was observed after 60 days of use. Compared with the conventional culture-based assay, the advantages of high throughput, timesaving and accurate quantification have made this method an ideal alternative for routine use.
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
Shuang Zhou, Yunfeng Zhao, Michael Mecklenburg, Dajin Yang, Bin Xie,