Testing for GMOs
The growing number of food companies getting their products non-GMO verified is increasing the demand for GMO testing, according to labs that test for GMOs.
“We’re doing a lot of testing for ingredient companies that are getting verified by the Non-GMO Project,” says Emily Dierking, genetics program director, Indiana Crop Improvement Association.
Chong Singsit, DNA laboratory manager at OMIC USA Inc., estimates that about 40 percent of his lab’s business is coming from Non-GMO Project verified companies.
While organic is a process-based certification, non-GMO verification is based on testing to ensure that products fall below certain thresholds for genetically modified material. This makes GMO testing essential to non-GMO verification programs such as the Non-GMO Project and NSF’s Non-GMO True North.
Increased interest with new GMO labeling law
The new national GMO labeling law recently signed by President Obama is also increasing demand for GMO testing.
“The amount of people interested in GMO testing has increased, particularly after the new GMO labeling bill was signed,” says Sergio Sanchez, vice president of analytical service at IEH Laboratories & Consulting Group, Inc.
Brent Pohlman, president of Midwest Laboratories, says he expects the demand for testing to increase as food companies become more aware of the GMO labeling law.
“Most food producers are looking more closely at their suppliers with respect to their finished products,” Pohlman says. “Food producers want to know if their suppliers are using materials that contain GMOs and what those traits are as well as materials that are non-GMO.”
Demand for testing is part of a larger trend, says Mahni Ghorashi, co-founder of Clear Labs. “Consumer demand for increased transparency is also a huge driver in this industry. Most brands are realizing this is something wanted by their consumers.”
GMO testing methods: strip test and PCR
The two main GMO test methods are protein-based lateral flow strip tests and DNA-based polymerase chain reaction (PCR).
Strip tests detect specific proteins produced by genetically modified DNA in GM crops. The test works similar to a home pregnancy test and produces results in two to five minutes. Strip tests are commonly used at grain elevators or other on-site locations where a fast, “yes or no” answer is needed. The main advantages are convenience, speed, user-friendliness, and low-cost. Strip tests work best on raw grains, but are limited in detecting proteins in processed foods because heat processes break down proteins, making detection difficult.
PCR, which is performed in a laboratory, is considered the most sensitive and precise GMO test method because it allows direct analysis of the DNA. In general there are two PCR methods: qualitative and “real-time” quantitative. Qualitative provides a “yes or no” result on the presence of GM DNA in a sample. Real-time quantifies the amount of GM DNA found in a sample. PCR is the only method that can effectively detect GMOs in processed foods. PCR is very sensitive; it can quantify GM content to .01 percent. However, a PCR analysis can take up to 3 days and costs significantly more than strip tests.
Both methods used in IP systems, importance of sampling
Many companies use both tests as part of an identity preservation system. A strip test is used as an initial screen to see if GMOs are present, and then PCR will be used to quantify the amount of GM material present.
“The two systems work well in conjunction; both are integral parts of identity preservation systems,” says Jamie Welch, a scientist at EnviroLogix, Inc., which manufactures strip tests. “Both have benefits and drawbacks.”
Welch says that getting a representative sample for testing is one of the most critical aspects of non-GMO verification, along with testing and traceability. In general the larger the sample size, the more representative it will be of an entire lot or truckload of grain, and the more accurate and sensitive the test will be. For example, a sample size of at least 10,000 kernels is recommended by several labs for unprocessed grain or beans.
The Non-GMO Project and other non-GMO certification programs set action thresholds for the percentage of GMO contamination they will allow. The most common threshold is 0.9 percent, which is the threshold for GMO labeling in Europe. The Non-GMO Project has thresholds for seed (0.25 percent), animal feed (5 percent), and food products (0.9 percent).
New technologies on the horizon
There are ongoing efforts to make GMO testing simpler, faster, and more economical.
EnviroLogix has developed a rapid molecular detection system called DNAble that is like a portable PCR system. Like PCR, DNAble can detect transgenic DNA in grains or processed products, but the entire process is faster.
“It does what PCR does but with a crude sample in less than 10 minutes onsite and with less sophisticated equipment,” says Dean Layton, senior vice president of marketing, sales, and business development at Envirologix. “Anyone that has a basic lab setup but needs real time point of need answers could benefit from it.”
California-based Clear Labs has developed a new GMO test based on “Next-Generation Sequencing” (NGS) technology. While strip and PCR tests target specific proteins or DNA sequences, NGS “casts a wide net across all possible genes, and can identify all possible GMO events in one test,” says company co-founder Mahni Ghorashi.
NGS is a breakthrough technology, according to Ghorashi. “Food safety will be transformed by this technology. It promises to open up a new level of transparency for the food industry and consumers.”
Non-GMO Project approved labs
The Non-GMO Project has approved a growing number of labs for GMO testing. Some of the requirements to gain approval include ISO 17025 accreditation, proof that a lab has tests for all GMO traits on the market, and participation in GMO testing proficiency trials, among others.
When choosing a GMO testing lab, many experts recommended looking for labs that meet those requirements. And while providing high-tech solutions to GMO challenges, labs should also deliver old-fashioned customer service.
“I’d be looking for service and accuracy, timely results, and a lab that is good to work with,” says Mike Stahr, lab manager at Iowa State University Seed Laboratory.
A list of GMO testing laboratories approved by the Non-GMO Project is available at http://www.nongmoproject.org/product-verification/testing-labs/.