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With the increasing number of genetically modified (GM) events, unauthorized GMO releases into the food market have increased dramatically, and many countries have developed detection tools for them. This study described the qualitative and quantitative detection methods of unauthorized the GM wheat MON71800 with a reference plasmid (pGEM-M71800). The wheat acetyl-CoA carboxylase (acc) gene was used as the endogenous gene. The plasmid pGEM-M71800, which contains both the acc gene and the event-specific target MON71800, was constructed as a positive control for the qualitative and quantitative analyses. The limit of detection in the qualitative PCR assay was approximately 10 copies. In the quantitative PCR assay, the standard deviation and relative standard deviation repeatability values ranged from 0.06 to 0.25 and from 0.23% to 1.12%, respectively. This study supplies a powerful and very simple but accurate detection strategy for unauthorized GM wheat MON71800 that utilizes a single calibrator plasmid., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

One novel standard reference plasmid, namely pUC-RICE5, was constructed as a positive control and calibrator for event-specific qualitative and quantitative detection of genetically modified (GM) rice (Bt63, Kemingdao1, Kefeng6, Kefeng8, and LLRice62). pUC-RICE5 contained fragments of a rice-specific endogenous reference gene ( sucrose phosphate synthase ) as well as the five GM rice events. An existing qualitative PCR assay approach was modified using pUC-RICE5 to create a quantitative method with limits of detection correlating to approximately 1–10 copies of rice haploid genomes. In this quantitative PCR assay, the square regression coefficients ranged from 0.993 to 1.000. The standard deviation and relative standard deviation values for repeatability ranged from 0.02 to 0.22 and 0.10% to 0.67%, respectively. The Ministry of Food and Drug Safety (Korea) validated the method and the results suggest it could be used routinely to identify five GM rice events. [ABSTRACT FROM AUTHOR]

A novel standard reference plasmid (pGEM-PAPAYA3) was constructed as a positive control and reference standard for event-specific qualitative and quantitative detection of genetically modified (GM) papaya (55-1, 16-0-1, and Huanong No.1). The plasmid pGEM-PAPAYA3 contained the specific fragments of papaya endogenous reference gene chymopapain and the 3 GM papaya events. The qualitative PCR assay using pGEM-PAPAYA3 was established with a limit of detection correlating to approximately 5–50 copies of papaya haploid genomes. In the quantitative PCR assay, the square regression coefficients ( R 2 ) ranged from 0.993 to 0.997. The standard deviation and relative standard deviation values for repeatability ranged from 0.04 to 0.25 and 0.05%–0.86%, respectively. The method was used to test 11 papaya products purchased from Thailand, China, the Philippines and the USA, and the results revealed 2 varieties of GM papaya in 5 of the 11 samples tested. These results indicate the developed detection methods with the standard reference plasmid are applicable for identifying 3 GM papaya events. [ABSTRACT FROM AUTHOR]