Italian researchers have developed a novel assay for DNA sensing of genetically modified (GM) soya based on the use of magnetic microbeads functionalised with PNA (peptide nucleic acid) probes and a subsequent read-out on screen-printed electrode (SPE) substrates. The PNA probes bind to a complementary DNA target extracted from non-amplified genomic DNA from GM Roundup Ready soya. The microbeads are then separated using a magnet and visualised on the screen to enable discrimination between the GM and the non-GM soya. The method was validated by comparing the results to other DNA assays requiring preliminary amplification of target DNA via PCR (polymerase chain reaction).
The ability of the magnet bead assay to detect the presence of Roundup Ready soya DNA sequence was tested on genomic DNA extracts from European Reference Material soya flours, demonstrating the capability of the method to match the European Union regulation for labelling of food containing a percentage of GM products greater than 0,9%.
Read the abstract here