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Feng J.,Zhejiang Sci-Tech University | Liang Y.,Zhejiang Sci-Tech University | Wang F.,Korla Entry Exit Inspection and Quarantine Bureau | Chen J.,Zhejiang Sci-Tech University | Chen J.,Nanjing University of Technology
Journal of Nanoscience and Nanotechnology

Genetically modified (GM) tomatoes have been approved for commercialization in many countries since the first GM tomato FLAVR SAVR was permitted for planting in 1994. To meet the requirement of the GM tomatoes labeling policy, in this study we firstly set up the conventional PCR and multiplex PCR detection system for screening the universal elements transformed into tomato, such as cauliflower mosaic virus 35s (CaMV 35s promoter, nopaline synthase (nos) terminator of Agrobacterium tumefaciens, neomycinphosphotransferase (nptII) gene, and the specifically inserted heterologous DNA sequence between CaMV 35s promoter and anti-sense ethylene-forming enzyme (anti-EFE) gene in GM tomato "Huafan No. 1." Tomato lat52, mcpi, fru and apx genes were used as endogenous reference genes. Besides these, a Paraflo microfluidic microarray was also developed to screen the exogenous or endogenous genes of GM tomatoes. A total of 957 probes were designed, which can be classified into two categories according to their purpose: the first for screening GM plants from un-transgenic plants based on the common elements such as promoter, reporter and terminator genes, and the second for specific gene confirmation based on target sequences such as anti-EFE or aminocyclopropane cyclase synthase (acc) gene. To ensure the reliability of this method, different kinds of positive and negative controls (such as the probes complementary to cp gene of CaMV) were included in microarray detection system. Four tomato species were identified by means of these methods, and the results indicated that microarray is a high-throughput and more efficient screening method, which could complement PCR-based screening procedures by providing direct conclusive evidence and also may be useful to resolve masking of unknown events by known events Copyright © 2013 American Scientific Publishers All rights reserved. Source

Wang F.,Korla Entry Exit Inspection and Quarantine Bureau | Zhang X.,Xinjiang Entry exit Inspection and Quarantine Bureau | Feng J.,Zhejiang Sci-Tech University | Wang Z.,Guangzhou Entry Exit Inspection And Quarantine Bureau | Wang P.,Korla Entry Exit Inspection and Quarantine Bureau
European Food Research and Technology

With the increase in number of the genetically modified (GM) crops authorized worldwide and specific labeling legislation established by many countries, a reliable and efficient method for routine screening of raw material or processed food products needs to be developed. In this paper, a quadruplex quantitative real-time PCR (qPCR) system is described which allows simultaneous detection of one tomato endogenous gene and three most frequently used transgenic elements in GM products: cauliflower mosaic virus 35S promoter, Agrobacterium tumefaciens nopaline synthase terminator, and neomycin phosphotransferase II gene. The specificities of the assays are optimized and validated. In the quadruplex qPCR system, the detection ranges for all of the four genes were determined to be 8-80,000 copies per reaction. Finally, the established detection system was applied in amplification of exogenous and endogenous genes from 33 raw materials and 35 processed products samples. The results indicate that quadruplex qPCR method is feasible for screening of GM tomato products, even for some processed food. As this detection system could be easily applied to the detection of transgenic elements in other plant species, we expect it will meet the challenges of routine GM crop detection resulting from a rapid increase in the number of GM crops in the future. © 2014 Springer-Verlag Berlin Heidelberg. Source

Zhang X.,Xinjiang University | Liu Y.,Korla Entry Exit Inspection and Quarantine Bureau | Wang P.,Korla Entry Exit Inspection and Quarantine Bureau | Wang J.,Xinjiang University | Feng S.,Xinjiang University
Chinese Journal of Chromatography (Se Pu)

An ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was proposed for the simultaneous determination of eight additives (Irgafos 168 (tri(2. 4-di-tert-butylphenyl)phosphite), Irganox 1076 (octadecyl-β-(M4-hydroxy-3, 5-di-tert-butyl- phenyl)propionate), Irganox 1010 (pentaerythritol tetrakys 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), BHA (butyl hydroxy anisole), TBHQ (tertiary butylhydroqui-none), PG (propyl gallate), DG (dodecyl gallate), UV-326 (2-(2'-hydroxyl-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole) in food packaging materials. After extracted by chlo-romethane through ultrasonic extraction, the samples were analyzed by UPLC-MS/MS. The chromatographic conditions were optimized, and the best separation was obtained on a Waters BEH-C18 column (50 mm×2. 1mm, 1. 7 μm) with gradient elution of 0. 059% acetic acid solution and methanol. The analysis was performed by UPLC-MS/MS with electrospray ionization (ESI) source in switching between the positive and negative ion modes in one run for multiple reaction monitoring. The eight additives showed good linear relationships in the ranges with all the correlation coefficients (R2) more than 0. 993. The limits of detection (LODs, S/N=3) and limits of quantitation (LOQs, S/N- 10) of this method were 0. 13-5. 50μg/L and 0. 45-17. 50μg/L, respectively. The recoveries were in the range of 63. 9%-127. 0% with all the RSDs ≤ 15.8% (n=6). This method is simple, accurate and effective for the analysis of the eight additives in food packaging materials. Source

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