Swiss company Syngenta recently announced that it had accidentally sold unapproved genetically modified seed corn in the US for four years, resulting in about 133 million kilograms of the corn making its way into the food chain.
Officials for the company, Syngenta, and the US Environmental Protection Agency insisted there is no danger to human health.
However, food companies wanting to perform PCR testing for their products to confirm the absence of the seed corn Bt10, may want to use Genetic ID's recently launched DNA-based test.
"The accidental release of Bt10 is an unfortunate situation for many companies exporting to markets already concerned about the presence of GMOs," said Bill Thompson, CEO of Genetic ID.
PCR is recognized internationally as the most sensitive and accurate test for GM grains and foods, according to the company. Other methods such as ELISA and lateral flow "strip" tests detect the genetically modified protein expressed by the GM plant, but protein expression can vary throughout the plant, making accurate GM detection difficult.
PCR, in contrast, is said to directly detect the GM DNA sequence, thus providing greater analytical accuracy.
"In the case of Bt10, protein tests cannot distinguish this GMO from Bt11, because the same protein is produced in both Bt10 and Bt11. Thus PCR is the only method capable of ascertaining the presence/absence of Bt10," said the company.
The firm offers its test for Bt10 through its laboratories in the US, Germany, and Japan, as well as through its Global Laboratory Alliance members in Brazil, Hong Kong, India, Japan, Singapore, South Korea, Taiwan, the UK and the US.
Between 2001 and 2004, Syngenta accidentally sold an unapproved corn variety called Bt 10, mistaking it for the approved variety Bt 11. Both varieties produce a bacterial toxin that kills insects, using the same inserted gene and producing the same protein. The only difference is the location of the inserted gene, according to Syngenta.
The company says it discovered the mistake for itself when it switched to a new quality control system that tests for DNA directly. Previously it had tested only for proteins, which meant the two varieties appeared identical.
In all, about 15,000 hectares in four US states were planted with the unapproved variety. This amounts to about 0.01 percent of the corn grown in the US over those four years. On average, about 70 percent of corn in the US is fed to animals, while the other 30 percent is consumed directly by people.