A cotton-specific gene, stearoyl-ACP desaturase, used as a reference for qualitative and real-time quantitative polymerase chain reaction detection of genetically modified organisms

2006 ◽  
Vol 86 (7) ◽  
pp. 1103-1109 ◽  
Author(s):  
Wen-Tao Xu ◽  
Kun-Lun Huang ◽  
Ying Wang ◽  
Hong-Xing Zhang ◽  
Yun-Bo Luo
Keyword(s):  
Polymerase Chain Reaction ◽  
Real Time ◽  
Genetically Modified Organisms ◽  
Genetically Modified ◽  
Quantitative Polymerase Chain Reaction ◽  
Specific Gene ◽  
Polymerase Chain Reaction Detection ◽  
Chain Reaction ◽  
Polymerase Chain

scholarly journals Quantitation of 35S Promoter in Maize DNA Extracts from Genetically Modified Organisms Using Real-Time Polymerase Chain Reaction, Part 2: Interlaboratory Study

2005 ◽  
Vol 88 (2) ◽  
pp. 558-573 ◽  
Author(s):  
Max Feinberg ◽  
Sophie Fernandez ◽  
Sylvanie Cassard ◽  
Chrystèle Charles-Delobel ◽  
Yves Bertheau ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Real Time ◽  
Genetically Modified Organisms ◽  
Genetically Modified ◽  
Interlaboratory Study ◽  
Performance Criteria ◽  
Tolerance Interval ◽  
Chain Reaction ◽  
Qrt Pcr ◽  
Polymerase Chain

Abstract The European Committee for Standardization (CEN) and the European Network of GMO Working Laboratories have proposed development of a modular strategy for stepwise validation of complex analytical techniques. When applied to the quantitation of genetically modified organisms (GMOs) in food products, the instrumental quantitation step of the technique is separately validated from the DNA extraction step to better control the sources of uncertainty and facilitate the validation of GMO-specific polymerase chain reaction (PCR) tests. This paper presents the results of an interlaboratory study on the quantitation step of the method standardized by CEN for the detection of a regulatory element commonly inserted in GMO maize-based foods. This is focused on the quantitation of P35S promoter through using the quantitative real-time PCR (QRT-PCR). Fifteen French laboratories participated in the interlaboratory study of the P35S quantitation operating procedure on DNA extract samples using either the thermal cycler ABI Prism® 7700 (Applied Biosystems, Foster City, CA) or Light Cycler® (Roche Diagnostics, Indianapolis, IN). Attention was focused on DNA extract samples used to calibrate the method and unknown extract samples. Data were processed according to the recommendations of ISO 5725 standard. Performance criteria, obtained using the robust algorithm, were compared to the classic data processing after rejection of outliers by the Cochran and Grubbs tests. Two laboratories were detected as outliers by the Grubbs test. The robust precision criteria gave values between the classical values estimated before and after rejection of the outliers. Using the robust method, the relative expanded uncertainty by the quantitation method is about 20% for a 1% Bt176 content, whereas it can reach 40% for a 0.1% Bt176. The performances of the quantitation assay are relevant to the application of the European regulation, which has an accepted tolerance interval of about ±50%. These data were fitted to a power model (r2 = 0.96). Thanks to this model, it is possible to propose an estimation of uncertainty of the QRT-PCR quantitation step and an uncertainty budget depending on the analytical conditions.

Development of AFLP-derived, functionally specific markers for environmental persistence studies of fungal strains

2006 ◽  
Vol 52 (5) ◽  
pp. 451-461 ◽  
Author(s):  
S S Hynes ◽  
O Chaudhry ◽  
M A Providenti ◽  
M L Smith
Keyword(s):  
Polymerase Chain Reaction ◽  
Real Time ◽  
Genetically Modified Organisms ◽  
Quantitative Polymerase Chain Reaction ◽  
Pcr Primers ◽  
Chain Reaction ◽  
Environmental Persistence ◽  
Fungal Strains ◽  
Target Dna ◽  
Polymerase Chain

The ability to rapidly identify and quantify a microbial strain in a complex environmental sample has widespread applications in ecology, epidemiology, and industry. In this study, we describe a rapid method to obtain functionally specific genetic markers that can be used in conjunction with standard or real-time polymerase chain reaction (PCR) to determine the abundance of target fungal strains in selected environmental samples. The method involves sequencing of randomly cloned AFLP (amplified fragment length polymorphism) products from the target organism and the design of PCR primers internal to the AFLP fragments. The strain-specific markers were used to determine the fate of three industrially relevant fungi, Aspergillus niger, Aspergillus oryzae, and Chaetomium globosum, during a 4 month soil microcosm experiment. The persistence of each of the three fungal strains inoculated separately into intact soil microcosms was determined by PCR analyses of DNA directly extracted from soil. Presence and absence data based on standard PCR and quantification of the target DNA by real-time PCR showed that all three strains declined after inoculation (~14-, 32-, and 4-fold for A. niger, A. oryzae, and C. globosum, respectively) but remained detectable at the end of the experiment, suggesting that these strains would survive for extended periods if released into nature.Key words: Canada domestic substances list (DSL), Canadian Environmental Protection Act (CEPA), genetically modified organisms (GMO), quantitative polymerase chain reaction (qPCR).

scholarly journals Real-Time Polymerase Chain Reaction Detection of Cauliflower mosaic virus to Complement the 35S Screening Assay for Genetically Modified Organisms

2005 ◽  
Vol 88 (3) ◽  
pp. 814-822 ◽  
Author(s):  
Katarina Cankar ◽  
Maja Ravnikar ◽  
Jana Žel ◽  
Kristina Gruden ◽  
Nataša Toplak
Keyword(s):  
Polymerase Chain Reaction ◽  
Mosaic Virus ◽  
Real Time ◽  
Genetically Modified Organisms ◽  
Genetically Modified ◽  
Pcr Amplification ◽  
Cauliflower Mosaic Virus ◽  
Chain Reaction ◽  
Screening Assay ◽  
Polymerase Chain

Abstract Labeling of genetically modified organisms (GMOs) is now in place in many countries, including the European Union, in order to guarantee the consumer's choice between GM and non-GM products. Screening of samples is performed by polymerase chain reaction (PCR) amplification of regulatory sequences frequently introduced into genetically modified plants. Primers for the 35S promoter from Cauliflower mosaic virus (CaMV) are those most frequently used. In virus-infected plants or in samples contaminated with plant material carrying the virus, false-positive results can consequently occur. A system for real-time PCR using a TaqMan minor groove binder probe was designed that allows recognition of virus coat protein in the sample, thus allowing differentiation between transgenic and virus-infected samples. We measured the efficiency of PCR amplification, limits of detection and quantification, range of linearity, and repeatability of the assay in order to assess the applicability of the assay for routine analysis. The specificity of the detection system was tested on various virus isolates and plant species. All 8 CaMV isolates were successfully amplified using the designed system. No cross-reactivity was detected with DNA from 3 isolates of the closely related Carnation etched ring virus. Primers do not amplify plant DNA from available genetically modified maize and soybean lines or from different species of Brassicaceae or Solanaceae that are natural hosts for CaMV. We evaluated the assay for different food matrixes by spiking CaMV DNA into DNA from food samples and have successfully amplified CaMV from all samples. The assay was tested on rapeseed samples from routine GMO testing that were positive in the 35S screening assay, and the presence of the virus was confirmed.

Detection of nonauthorized genetically modified organisms using differential quantitative polymerase chain reaction: application to 35S in maize

2008 ◽  
Vol 376 (2) ◽  
pp. 189-199 ◽  
Author(s):  
Katarina Cankar ◽  
Valérie Chauvensy-Ancel ◽  
Marie-Noelle Fortabat ◽  
Kristina Gruden ◽  
André Kobilinsky ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Genetically Modified Organisms ◽  
Genetically Modified ◽  
Quantitative Polymerase Chain Reaction ◽  
Chain Reaction ◽  
Polymerase Chain
Sign in / Sign up

Export Citation Format

Share Document