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The Scientific World Journal
Volume 2012, Article ID 159456, 10 pages
http://dx.doi.org/10.1100/2012/159456
Research Article

Sensitivity and Selectivity on Aptamer-Based Assay: The Determination of Tetracycline Residue in Bovine Milk

Department of Chemistry, Seoul Women's University, Seoul 139-774, Republic of Korea

Received 12 October 2011; Accepted 17 November 2011

Academic Editors: C. Pistos, A. Sabarudin, and A. Scozzafava

Copyright © 2012 Sohee Jeong and Insook Rhee Paeng. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

A competitive enzyme-linked aptamer assay (ELAA) to detect tetracycline in milk was performed by using two different aptamers individually; one is 76 mer-DNA aptamer and the other is 57 mer-RNA aptamer. The best optimum condition was obtained without monovalent ion, Na+ and also by adding no Mg2+ ion in the assay buffer, along with RT incubation. The optimized ELAA showed a good sensitivity (LOD of 2.10 × 10−8 M) with a wide dynamic range (3.16 × 10−8 M ~ 3.16 × 10−4 M). In addition, the average R.S.D. across all data points of the curve was less than 2.5% with good recoveries (~101.8%) from the milk media. Thus, this method provides a good tool to monitor tetracycline in milk from MRLs’ point of view. However, this ELAA method was not superior to the ELISA method in terms of specificity. This paper describes that it does not always give better sensitivity and specificity in assays even though aptamers have several advantages over antibodies and have been known to be good binders for binding assays.