Agilent Technologies claims to have found a new way to detect genetically modified (GM) content in food products that allows rapid screening using the company's 2100 bioanalyser with its DNA 500 LabChip.

The company's scientists often work on analytical chemistry problems that customers bring to them, but this project was not the result of a request. "We had been looking for some time at methods for the detection of genetically modified food products using our instrument," said Mark Jensen, an Agilent applications chemist, who worked on the project. "Rather than wait for a specific customer to ask for it, this is one we did preemptively."

Work on the method took about three months and was completed several weeks ago, he said. The company is now spreading the word that the Agilent 2100 bioanalyser and DNA 500 LabChip can be used to resolve and detect multiplex polymerase chain reactions (PCRs) that correspond to GM DNA segments in corn and soybeans. The method is expected to be of most use to laboratories that screen food products and may find more interest in Europe, where restrictions are tighter and concerns over GM foods are greater than elsewhere, Jensen said.

PCR allows scientists to purify and multiply billions of copies of DNA in the span of hours. Multiplex PCR enables screening of multiple target DNA sequences and GM detection in a single reaction, according to various academic and government web sites describing the process.

"The big advantage with [using] the bioanalyser is that it basically does a gel-type profile of DNA fragments, but it does it with a much higher resolution than your typical high-throughput gels would be capable of," he said. The Agilent method involves detecting the presence of a DNA molecule, but the bioanalyser also can analyse proteins left behind in the DNA sample, he said. All of this makes for more accurate testing, which can eliminate the number of quantitative tests that are called for.

Testing that analyses proteins is more difficult to do, according to the web site of Entransfood, a food safety network subsidised by the European Commission. Quantitative testing is an optional step to end the detection process, Entransfood said. It is used to determine how much GM material is in a sample.

Such tests run about US$300 per result, Jensen said. "Obviously, there's a wide variety of GMOs out there, so if you want to do a quantitative test on each one you would wind up spending literally thousands of dollars."