title: An RNA-aptamer-based assay for the detection and analysis of malachite green and leucomalachite green residues in fish tissue.
abstract: A robust screening assay employing solid phase extraction (SPE) followed by a novel aptamer-based procedure is presented for the rapid detection and semiquantitation of the triphenylmethane dye, Malachite Green (MG) and its primary metabolite Leucomalachite Green (LMG) in fish tissue. To the authors' knowledge, this is the first reported use of an RNA aptamer for the development of a diagnostic assay for the detection of chemical residues in food. The aptamer based screening assay is found to be highly specific for MG; but has negligible affinity for the LMG metabolite. However, because the LMG metabolite is lipophilic and known to be highly persistent in tissues, an oxidation step has been incorporated within the sample cleanup procedure to ensure that all LMG residues are converted to MG prior to measurement. This article provides evidence that an oligonucleotide aptamer can be used as an alternative recognition element to conventional antibodies with application to the detection of residues in food. Furthermore, this finding has the future potential to reduce the number of animals currently being used in the production of antibodies for immunodiagnostic kits.
authors.affiliation: Food and Environment Research Agency, Sand Hutton, York YO41 1LZ North Yorkshire, United Kingdom. sara.stead@fera.gsi.gov.uk
authors.forename: Sara L
authors.initials: SL
authors.lastname: Stead
authors.forename: Helen
authors.initials: H
authors.lastname: Ashwin
authors.forename: Brian
authors.initials: B
authors.lastname: Johnston
authors.forename: Anne
authors.initials: A
authors.lastname: Dallas
authors.forename: Sergei A
authors.initials: SA
authors.lastname: Kazakov
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Tarbin
authors.forename: Matthew
authors.initials: M
authors.lastname: Sharman
authors.forename: Jack
authors.initials: J
authors.lastname: Kay
authors.forename: Brendan J
authors.initials: BJ
authors.lastname: Keely
mesh_terms: D000818:Animals; D052157:Aptamers, Nucleotide / Q000737:chemistry*; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods*; D005399:Fishes / Q000378:metabolism; D005506:Food Contamination / Q000032:analysis; D012313:RNA / Q000737:chemistry*; D012394:Rosaniline Dyes / Q000032:analysis* / Q000302:isolation & purification; D052616:Solid Phase Extraction
chemical_list: D052157:Aptamers, Nucleotide; D012394:Rosaniline Dyes; C005095:malachite green; D012313:RNA; C015320:leucomalachite green