The British government is considering forcing biotech companies to use DNA bar-coding to identify genetically modified organisms, reports the New Scientist journal.
This week the National Institute of Agricultural Botany (NIAB) in Cambridge was granted a patent on a DNA bar-coding technique. The technology would make it easier for regulators to trace GM food or detect crops that have been contaminated by GM strains. It could also have wider uses. Banknotes or designer clothes made from bar-coded cotton would be harder to counterfeit.
A spokesman for Britain's Department for Environment, Food and Rural Affairs (DEFRA) claims that it is too early to commit to any one method, but told the New Scientist that such technology would be "actively encouraged". A recent European Union directive gives governments the power to make it compulsory.
"We have been talking about techniques for encoding unique identifiers in the context of GMOs for some time," said Howard Dalton, DEFRA's chief scientific adviser. "Any development which would help in the process of detecting and identifying GMOs would be welcomed."
The idea is to add the same unique sequence to all GM organisms, regardless of how else they are modified. That means a single, simple DNA test could identify any product as GM if it contains intact DNA. Since such a sequence would not code for any protein, it would not affect a plant's properties. Most creatures' genomes are already littered with vast stretches of non-coding DNA.
DNA bar codes could also provide detailed information about a product. NIAB's patent describes how a series of sequences that contain compressed information - such as which company made the GM organisms and what modifications it has - could be added. "Simpler techniques for access to that information will help us ensure effective traceability and labelling through the food supply chain. This will ensure consumer choice and increase confidence," added Dalton.
"Detecting GM products is difficult at present, because you have to know what you are looking for," said Derek Matthews, a molecular biologist at NIAB. "For example, you need to know the short sequences that flank any added piece of DNA, or the sequence of added genes or of the DNA regions that control their activity."
But biotech companies are often reluctant to reveal such information because of fears that other companies may copy their technology. For instance, Gro-Ingunn Hemre at the National Institute of Nutrition and Seafood Research in Bergen, Norway, has been trying for nearly three years to get data and material from a number of biotech companies for a research project, without success, writes the journal.
The recent EU directive also requires biotech companies to supply detailed information on every GM product, including how to identify it, before approval. But companies are still reluctant to cooperate. "It's very, very difficult to get stuff out of them, even though they are legally obliged," said Matthews.
According to the article, Matthews believes that most companies would prefer genetic bar codes, since this would allow them to label their products without giving away any secrets. The Agricultural Biotechnology Council, which represents the British industry, has given the idea a cautious welcome.
