title: Development of melting temperature-based SYBR Green I polymerase chain reaction methods for multiplex genetically modified organism detection.
abstract: Commercialization of several genetically modified crops has been approved worldwide to date. Uniplex polymerase chain reaction (PCR)-based methods to identify these different insertion events have been developed, but their use in the analysis of all commercially available genetically modified organisms (GMOs) is becoming progressively insufficient. These methods require a large number of assays to detect all possible GMOs present in the sample and thereby the development of multiplex PCR systems using combined probes and primers targeted to sequences specific to various GMOs is needed for detection of this increasing number of GMOs. Here we report on the development of a multiplex real-time PCR suitable for multiple GMO identification, based on the intercalating dye SYBR Green I and the analysis of the melting curves of the amplified products. Using this method, different amplification products specific for Maximizer 176, Bt11, MON810, and GA21 maize and for GTS 40-3-2 soybean were obtained and identified by their specific Tm. We have combined amplification of these products in a number of multiplex reactions and show the suitability of the methods for identification of GMOs with a sensitivity of 0.1% in duplex reactions. The described methods offer an economic and simple alternative to real-time PCR systems based on sequence-specific probes (i.e., TaqMan chemistry). These methods can be used as selection tests and further optimized for uniplex GMO quantification.
authors.affiliation: Dpt de Genètica Molecular, Institut de Biologia Molecular de Barcelona, Centro de Investigación y Desarrollo-Consejo Superior de Investigaciones Científicas, Jordi Girona 18-26, 08034, Barcelona, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Hernández
authors.forename: David
authors.initials: D
authors.lastname: Rodríguez-Lázaro
authors.forename: Teresa
authors.initials: T
authors.lastname: Esteve
authors.forename: Salomé
authors.initials: S
authors.lastname: Prat
authors.forename: Maria
authors.initials: M
authors.lastname: Pla
mesh_terms: D052160:Benzothiazoles; D029688:Brassica napus / Q000235:genetics; D018744:DNA, Plant / Q000032:analysis; D003959:Diamines; D005456:Fluorescent Dyes / Q000737:chemistry*; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods; D009930:Organic Chemicals / Q000737:chemistry*; D030821:Plants, Genetically Modified / Q000145:classification / Q000235:genetics*; D016133:Polymerase Chain Reaction / Q000379:methods*; D011804:Quinolines; D013025:Glycine max / Q000235:genetics; D013696:Temperature; D003313:Zea mays / Q000235:genetics
chemical_list: D052160:Benzothiazoles; D018744:DNA, Plant; D003959:Diamines; D005456:Fluorescent Dyes; D009930:Organic Chemicals; D011804:Quinolines; C098022:SYBR Green I