Selection and Identification of Chloramphenicol-Specific DNA Aptamers by Mag-SELEX.
Chloramphenicol (CAP) has been widely used to treat bacterial infections in livestock and aquatic animals. To reduce the risk of CAP residues, an efficient technology to rapidly detect CAP residues in animal-sourced food is expressly needed. In this study, magnetic bead-based systematic evolution of ligands by exponential enrichment (Mag-SELEX) strategy was performed to select and identify CAP-specific single-stranded DNA (ssDNA) aptamers from a random oligonucleotide library. After nine rounds of selection, five potential ssDNA aptamers were selected. Low homology indicated that they might belong to different families. To identify an aptamer with the highest affinity for CAP, the dissociation constant (Kd) values of these selected aptamers were determined. The lowest Kdvalues of two potential aptamers (i.e., No. 4 and No. 5) were, respectively, 0.10162 ± 0.0111 and 0.03224 ± 0.00819 μM, which were much lower than previously reported lowest Kdvalue (i.e., 0.766 μM) of CAP aptamer. Moreover, compared with No. 4, aptamer No. 5 had higher binding rate, which is quite different among those with CAP and with CAP's structural analogs (i.e., thiamphenicol (TAP) and florfenicol (FF)). These results indicated that the potential aptamer No. 5 with highest specificity and affinity for CAP would be an ideal aptamer for future detection of residual CAP in animal-sourced food.
Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China.
Ye
Y
Duan
Beijing Entry-Exit Inspection and Quarantine Bureau, Beijing, 100026, China.
Zhiqiang
Z
Gao
Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China.
Lihui
L
Wang
Beijing Senkang Biotechnology Development Co., Ltd, Beijing, 101400, China.
Huishan
H
Wang
Beijing Entry-Exit Inspection and Quarantine Bureau, Beijing, 100026, China. zhanghx@bjciq.gov.cn.
Hexiao
H
Zhang
Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China. lihao@mail.buct.edu.cn.
Hao
H
Li
D052157:Aptamers, Nucleotide / Q000737:chemistry / Q000378:metabolism*; D001483:Base Sequence; D002264:Carboxylic Acids / Q000737:chemistry; D002701:Chloramphenicol / Q000737:chemistry / Q000494:pharmacology*; D003001:Cloning, Molecular; D060328:Magnetic Phenomena; D008863:Microspheres; D009690:Nucleic Acid Conformation; D052156:SELEX Aptamer Technique / Q000379:methods*; D017422:Sequence Analysis, DNA; D017550:Spectroscopy, Fourier Transform Infrared
D052157:Aptamers, Nucleotide; D002264:Carboxylic Acids; D002701:Chloramphenicol
Chloramphenicol; Drug residue detection; Mag-SELEX; Specificity and affinity; ssDNA aptamer