MOLECULAR DIAGNOSTICS/GENOMICS: Easy bioluminescence approach detects genetically modified crop traces at high sensitivity

Genetically modified (GM) crops are increasingly the subject of concern among consumers—and those serving consumer needs.

Genetically modified (GM) crops are increasingly the subject of concern among consumers—and those serving consumer needs. Now a pair of technologies—a bioluminescent real-time reporter and loop-mediated isothermal amplification (LAMP)—has proven able, in combination, to identify products of genetic modification at low concentration. New research shows that the molecular diagnostics approach is able to recognize 0.1% GM contamination of corn, far below the European Union's current limit of 0.9%.1

GM crops are used not only as food, but also to produce proteins such as collagen in the pharmaceutical industry. The safety of these crops is much debated, however, and concern persists about whether man-made transgenes might contaminate wild populations and produce herbicide-resistant weeds. With its ability to deploy both in the field and in processing chains, the new approach promises to help shed light.

Real-time polymerase chain reaction (RT-PCR) and fluorescence-based determination of amplification is the standard method for assessing the GM content of a crop, but the approach involves exacting extraction procedures, temperature cycling, and complex optics. To overcome these limitations, researchers from Lumora Ltd. (Ely, England) assessed whether they could use a relatively simple approach: LAMP to amplify DNA at a constant temperature and bioluminescent output produced in real time (BART) to identify GM-specific DNA in real time.

Besides the ability of the LAMP-BART combination to detect as little as 0.1% GM contamination, the approach proved more tolerant of contaminating polysaccharides, meaning that the DNA cleanup process did not need to be as thorough. According to Guy Kiddle of Lumora, who led the research, "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."

1. G. Kiddle et al., BMC Biotechnol., 12, 15 (2012).

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