title: In vitro selection and characterization of DNA aptamers recognizing chloramphenicol.
abstract: Chloramphenicol (Cam), although an effective antibiotic, has lost favour due to some fatal side effects. Thus there is an urgent need for rapid and sensitive methods to detect residues in food, feed and environment. We engineered DNA aptamers that recognize Cam as their target, by conducting in vitro selections. Aptamers are nucleic acid recognition elements that are highly specific and sensitive towards their targets and can be synthetically produced in an animal-friendly manner, making them ethical innovative alternatives to antibodies. None of the isolated aptamers in this study shared sequence homology or structural similarities with each other, indicating that specific Cam recognition could be achieved by various DNA sequences under the selection conditions used. Analyzing the binding affinities of the sequences, demonstrated that dissociation constants (K(d)) in the extremely low micromolar range, which were lower than those previously reported for Cam-specific RNA aptamers, were achieved. The two best aptamers had G rich (>35%) nucleotide regions, an attribute distinguishing them from the rest and apparently responsible for their high selectivity and affinity (K(d)∼0.8 and 1μM respectively). These aptamers open up possibilities to allow easy detection of Cam via aptamer-based biosensors.
authors.affiliation: University of Antwerp, Department of Biology, Laboratory for Ecophysiology, Biochemistry and Toxicology, Groenenborgerlaan, Antwerp, Belgium. Jaytry.Mehta@ua.ac.be
authors.forename: Jaytry
authors.initials: J
authors.lastname: Mehta
authors.forename: Bieke
authors.initials: B
authors.lastname: Van Dorst
authors.forename: Elsa
authors.initials: E
authors.lastname: Rouah-Martin
authors.forename: Wouter
authors.initials: W
authors.lastname: Herrebout
authors.forename: Marie-Louise
authors.initials: ML
authors.lastname: Scippo
authors.forename: Ronny
authors.initials: R
authors.lastname: Blust
authors.forename: Johan
authors.initials: J
authors.lastname: Robbens
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D001483:Base Sequence; D015374:Biosensing Techniques; D002701:Chloramphenicol / Q000032:analysis*; D004247:DNA / Q000737:chemistry*; D006801:Humans; D007700:Kinetics; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation
chemical_list: D052157:Aptamers, Nucleotide; D002701:Chloramphenicol; D004247:DNA