The technology aims to monitor genetically modified (GM) crops, not only in the field but also during the food processing chain, said the researchers. Writing in BMC Biotechnology, they reveal that the technology can identify GM crops at concentrations as low as 0.1% using a combination of bioluminescent and isothermal amplification technologies – meaning the technique could be used to monitor for contamination with GM ingredients.
Under current EU regulations the threshold limit for ‘unavoidable presence’ of GM materials in crops is 0.9%. After this level, items containing approved GM products require labelling.
The authors, led by Dr Guy Kiddle from Lumora – a spin-out company of the University of Cambridge, UK – assessed whether they could use a technique known as loop mediated isothermal amplification (LAMP) to amplify DNA at a constant temperature before using a new technique called bioluminescent real time reporter (BART) to identify GM-specific DNA in real time.
Kiddle said that LAMP-BART was able to detect as little as 0.1% GM contamination of maize, and compared to PCR, was more tolerant of contaminating polysaccharides – meaning that the DNA clean-up process did not need to be as thorough.
"This method requires only basic equipment for DNA extraction and a constant temperature for DNA amplification and detection. Consequently LAMP-BART provides a 'field-ready' solution for monitoring GM crops and their interaction with wild plants or non-GM crops," he commented.
Lumora recently won the top prize for commercial innovation at the UK Biotechnology and Biological Sciences Research Council (BBSRC) innovation awards. The company won the award for the development of the BART system, which can be used to detect infectious organisms including bacteria and viruses using luciferase, the same enzyme which lights up fireflies.
The BART system triggers luciferase to produce light when it detects specific DNA or RNA sequences. By using DNA signals specific to GM crops, the researchers said the system can detect even very low levels of contamination.
The authors said that the LAMP-BART system is "an effective and sensitive technique for GM detection with significant potential for quantification even at low levels of contamination and in samples derived from crops such as maize with a large genome size.”
They added that the resilience of the system to acidic polysaccharides makes it ‘well suited’ to rapid sample preparation techniques ... “and hence to both high throughput laboratory settings and to portable GM detection applications.”
Source: BMC Biotechnology
Published online ahead of print, doi: 10.1186/1472-6750-12-15
“GMO detection using a bioluminescent real time reporter (BART) of loop mediated isothermal amplification (LAMP) suitable for field use”
Authors: G. Kiddle, P. Hardinge, N. Buttigieg, O. Gandelman, C. Pereira, et al