Optimised padlock probe ligation and microarray detection of multiple (non-authorised) GMOs in a single reaction

Area of Science:

• Food science and technology
• Molecular biology
• Genetics and genomics

Background:

• EU GMO regulations require event-specific detection methods for new GM crop varieties.
• Current methods are limited for detecting non-authorised GMOs (NAGs) in diverse food and feed matrices.
• Increasing GM ingredient diversity necessitates versatile detection strategies.

Purpose of the Study:

• To develop an innovative, scalable method for detecting both approved and non-authorised GMOs (NAGs).
• To address the challenge of identifying GMOs in complex DNA samples with multiple crop species.

Main Methods:

• Optimized padlock probe ligation in combination with microarray detection (PPLMD).
• Development of linear padlock probes targeting GMO events, elements, and species.
• Hybridization of probes to genomic DNA and visualization via microarray analysis.

Main Results:

• Tenplex PPLMD detected various genomic targets in Roundup-Ready soya, MON1445 cotton, and Bt176 maize down to 1%.
• Single-plex experiments achieved detection limits of 0.1%, comparable to standard quantitative PCR (qPCR).
• The PPLMD method demonstrated scalability and effectiveness in complex DNA samples.

Conclusions:

• The PPLMD approach represents a significant advancement for multiplex GMO detection in complex raw and derived products.
• This method is suitable for large-scale, real-life sample analysis.
• PPLMD enhances the ability to detect and identify NAGs that might otherwise go undetected.