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Digital PCR as an effective tool for GMO quantification in complex matrices

Bogožalec Košir, Alexandra, Demšar, Tina, Štebih, Dejan, Žel, Jana, Milavec, Mojca
Food chemistry 2019 v.294 pp. 73-78
DNA, droplets, genes, genetically modified organisms, monitoring, product authenticity, quantitative polymerase chain reaction, soybeans
The increased use of genetically modified organisms (GMOs) is accompanied by increased complexity of the matrices that contain GMOs. The most common DNA-based approach for GMO detection and quantification is real-time quantitative polymerase chain reaction (qPCR). However, as qPCR is sensitive to inhibitors and relies on standard curves for quantification, it has limited application in GMO quantification for complex matrices. To overcome this hurdle in DNA quantification, we present droplet digital PCR (ddPCR) assays that were designed to target ‘Roundup Ready’ soybean and the soybean reference gene. Three ddPCR assays were transferred from qPCR to QX100/QX200 ddPCR platforms and characterised. Together, the fitness-for-purpose study on four real-life samples and the use of a chamber-based PCR system, showed that dPCR has great potential to improve such measurements in GMO testing and monitoring of food authenticity.