title: Development and in-house validation of the event-specific qualitative and quantitative PCR detection methods for genetically modified cotton MON15985.
abstract: BACKGROUND
  To implement genetically modified organism (GMO) labeling regulations, an event-specific analysis method based on the junction sequence between exogenous integration and host genomic DNA has become the preferential approach for GMO identification and quantification.
  
  
  RESULTS
  In this study, specific primers and TaqMan probes based on the revealed 5'-end junction sequence of GM cotton MON15985 were designed, and qualitative and quantitative polymerase chain reaction (PCR) assays were established employing the designed primers and probes. In the qualitative PCR assay, the limit of detection (LOD) was 0.5 g kg(-1) in 100 ng total cotton genomic DNA, corresponding to about 17 copies of haploid cotton genomic DNA, and the LOD and limit of quantification (LOQ) for quantitative PCR assay were 10 and 17 copies of haploid cotton genomic DNA, respectively. Furthermore, the developed quantitative PCR assays were validated in-house by five different researchers. Also, five practical samples with known GM contents were quantified using the developed PCR assay in in-house validation, and the bias between the true and quantification values ranged from 2.06% to 12.59%.
  
  
  CONCLUSIONS
  This study shows that the developed qualitative and quantitative PCR methods are applicable for the identification and quantification of GM cotton MON15985 and its derivates.
authors.affiliation: GMO Detection Laboratory, SJTU-Bor Luh Food Safety Center, School of life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, PR China.
authors.forename: Lingxi
authors.initials: L
authors.lastname: Jiang
authors.forename: Litao
authors.initials: L
authors.lastname: Yang
authors.forename: Jun
authors.initials: J
authors.lastname: Rao
authors.forename: Jinchao
authors.initials: J
authors.lastname: Guo
authors.forename: Shu
authors.initials: S
authors.lastname: Wang
authors.forename: Jia
authors.initials: J
authors.lastname: Liu
authors.forename: Seonghun
authors.initials: S
authors.lastname: Lee
authors.forename: Dabing
authors.initials: D
authors.lastname: Zhang
mesh_terms: D001483:Base Sequence; D017931:DNA Primers; D018744:DNA, Plant / Q000032:analysis*; D018745:Genome, Plant; D003368:Gossypium / Q000235:genetics*; D006238:Haploidy; D057230:Limit of Detection; D030821:Plants, Genetically Modified / Q000235:genetics*; D016133:Polymerase Chain Reaction / Q000379:methods*
chemical_list: D017931:DNA Primers; D018744:DNA, Plant