• Jamie Welch, Technical Support Supervisor

Testing Methods for GMO Detection

Demand for genetically modified organism (GMO) labeling of food is growing, both domestically and internationally. A 2015 Nielsen survey titled “We Are What We Eat: Healthy Eating Trends Around The World” polled an international audience on food attitudes, including GMOs. The survey highlighted that 43% of global consumers consider “GMO-Free” to be very important when making purchasing decisions, and 33% of global consumers are willing to pay a premium for GMO-free products. In North America these figures are 32% and 25%, respectively. In the United States, Non-GMO certification organizations have emerged to provide verification and transparency in the voluntary GMO labeling of products. These include the Non-GMO Project and the newly announced Non-GMO True North certification offered by NSF International. Other U.S. companies choose to have their GMO testing process validated by the USDA’s Process Verification Program.

Sampling and testing are critical components of all non-GMO labeling certification programs to verify that the GMO content is below acceptance thresholds. If you decide to certify your product as Non-GMO, then accurate, representative sampling is an important first step. A knowledgeable industry expert or trusted online resource can help guide you in the creation of a statistically sound sampling protocol. Reliable testing can be accomplished by identifying foreign DNA, inserted into the genetically modified crop via biotechnology techniques, or by the proteins that are expressed in the leaf or seed of GMO crops as a result of the foreign DNA insertion. Protein detection and DNA detection, when used in conjunction, provide the most thorough testing program to verify the GMO content in products throughout the supply chain.

Protein detection is fast, easy, affordable and accurate. It allows you to quantitate GMO levels in raw grains onsite. Lateral flow strips are a proven technology that have been used successfully for over 15 years to originate grain for the non-GMO export market. Lateral flow strips allow grain receiving terminals to quickly assess the GMO content of a truck, railcar, bin, or barge. Commodities frequently tested are corn, soy, canola, and alfalfa. Strip reactions are completed with minimal steps and results can be interpreted in 5 minutes. Quantitative results are obtained by placing reacted strips in a reader, such as the EnviroLogix QuickScan. Technicians can then triage the incoming load based on the sample's GMO levels. All QuickScan GMO data is compiled into a spreadsheet, where testing reports for each load can be easily generated for complete traceability. Data capture capabilities are an integral component of the "farm to fork" traceability system.

As foods become more processed and products are exposed to elevated temperatures, DNA detection methods become necessary to quantify GMO levels. DNA testing for GMOs takes advantage of common genetic markers found in multiple GMO events. DNA analysis is the gold standard for GMO testing. New technology has emerged that will allow DNA-based testing to occur onsite, with a significant savings in cost, time and labor. By contrast, the standard polymerase chain reaction (PCR) testing is a laboratory-based method that requires highly trained personnel, expensive equipment, and several hours for sample preparation and analysis. A GMO analysis of a product with PCR typically costs $300-$500 per sample. PCR results are also quantitative and can be performed on final products or food ingredients. However, some products and ingredients are so highly processed that the DNA is not suitable for amplification and can’t be detected. In these circumstances, less processed precursor ingredients must be tested.

Many non-GMO grain originators utilize the onsite, rapid results of quantitative lateral flow strips to verify the GMO content in all incoming trucks. Testing every load limits the risk of non-GMO grain loads being mixed with loads of unacceptable GMO content. This could result in a cumulative GMO level above acceptable thresholds. Composite samples are sent out for DNA confirmatory testing. Consistent monitoring of incoming grain is a vital part of a complete GMO testing program. This builds confidence that the DNA testing conducted downstream on processed samples will be within acceptance levels.

For more specifics on GMO testing with protein and DNA technology, attend the Organic & Non-GMO Forum session presented by scientist and industry expert Jamie Welch on September 30. You can also learn more by contacting Jamie at techsupport@envirologix.com or visit the EnviroLogix website at http://www.envirologix.com/technology/.

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Lynda Kiernan is Editor with HighQuest Group Media and of the Oilseed & Grain News. If you would like to submit a contribution for consideration, please contact Ms. Kiernan at lkiernan@highquestgroup.com.

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