Validation of a sensitive DNA walking strategy to characterise unauthorised GMOs using model food matrices mimicking common rice products. (15th April 2015)

• Record Type: Journal Article
• Authors: Fraiture, Marie-Alice; Herman, Philippe; Taverniers, Isabel; De Loose, Marc; Van Nieuwerburgh, Filip; Deforce, Dieter; Roosens, Nancy H.
• Is Part Of: Food chemistry. Volume 173(2015)
• Page Start: 1259
• Page End: 1265
• Publication Date: 2015-04-15
• Subjects: Unauthorised GMO -- Detection -- Transgene flanking region -- DNA walking -- Sensitivity -- Rice food; Food -- Analysis -- Periodicals; Food -- Composition -- Periodicals; 664
• DOI: 10.1016/j.foodchem.2014.09.148
• Languages: English
• ISSNs: 0308-8146

Abstract

Highlights: The performance of the DNA walking method is assessed using model rice food matrices. The transgene flanking regions of the unauthorised GMO are detected as low as 10 HGEs. The presence of untargeted DNA does not affect the DNA walking method. This method is able to deal with degraded DNA from processed rice food matrices. Abstract: To identify unauthorised GMOs in food and feed matrices, an integrated approach has recently been developed targeting pCAMBIA family vectors, highly present in transgenic plants. Their presence is first assessed by qPCR screening and is subsequently confirmed by characterising the transgene flanking regions, using DNA walking. Here, the DNA walking performance has been thoroughly tested for the first time, regarding the targeted DNA quality and quantity. Several assays, on model food matrices mimicking common rice products, have allowed to determine the limit of detection as well as the potential effects of food mixture and processing. This detection system allows the identification of transgenic insertions as low as 10 HGEs and was not affected by the presence of untargeted DNA. Moreover, despite the clear impact of food processing on DNA quality, this method was able to cope with degraded DNA. Given its specificity, sensitivity, reliability, applicability and practicability, the proposed approach is a key detection tool, easily implementable in enforcement laboratories.