Technology race opens for GM test request

By Michael Byrnes

SYDNEY (Reuters): The global furor over genetically modified food is opening a technology race to produce portable mini-labs which diners could take on that big night out.

A simple dipstick test for GM food remains elusive.

But personal "micro-arrays", perhaps nestling between candles on the restaurant table, could check if one's gnocchi are GM- free.

"Your micro-array or mine?" might be the New Age mantra.

Micro-arrays are mainly a biological slide-reaction test for bacteria -- the word "array" refers to the test readings -- that can also be used for GM material.

Commercial production is some way away but consumer pressure for GM food labeling is winning the day over scientific skepticism about the validity or need for GM tests.

Serious battlelines are being drawn over whether GM content can be accurately measured to underpin labeling laws.

Australian and New Zealand health ministers met last month to consider strict laws requiring labeling of food containing even a trace of GM.

Pummeled by claim and counter-claim, the ministers considered label thresholds, costs, ethics and commercial implications for export markets.

Then they shelved an immediate decision when faced with a barrage of faxes from U.S. company Genetic ID, which claimed it could make exact GM measurements.

Founded by John Fagan, professor of Molecular Biology at Maharishi University, Genetic ID is typical of the GM maze.

Closely associated with movements opposing GM foods through Fagan's role with Maharishi Ayur-veda Products, Genetic ID says its tests are accurate and sells test technique licensees.

"My worry is that such a claim might give a false sense of security that it's all over bar the shouting in terms of having an analytical tool" Dr. Stuart Boag, principal projects director of Australian Government Analytical Laboratories (AGAL), told Reuters.

"I just don't think it's realistic."

Australia's passionate consumer movement has no such fears.

"So often now food regulation is funded by the food industry...there's a very clear commercial interest in running a line," said Mara Bun, manager for policy and public affairs at the Australian Consumers Association. "Obviously there's a big, big marketplace here."

AGAL's Sydney lab does drug tests for the International Olympic Committee, conducts police forensic analysis for all drug seizures in Australia and tests food for the Australian quarantine service, national airline Qantas and major food chains.

GM test requests are its latest growth sector.

Cabinets, refrigerators and counter tops in the molecular biology lab are full of samples sent in for testing. A scientist points to a plastic packet of fermented soy flour from Asia.

"That's very difficult," he says.

Testing for GM content in bread, milk and unprocessed soy is relatively simple. GM is more difficult to find in chocolate. The further products progress down the processing chain the more difficult testing and measurement of GM content becomes.

It is impossible to isolate GM content in soy sauce, scientists say. GMs are virtually impossible to find in processed cooking oils because of refining, leaving the prospect of tests showing oil GM-free even though produced from a modified oil seed.

Most margarine contains cottonseed oil and GM cotton crops are spreading globally -- yet lab tests show margarine GM-free.

The EU recently ruled that all food products carry labels declaring GM content at more than one percent. Australian and New Zealand health ministers considered labeling for even a trace.

"One percent? One point one percent? Nought point nine percent?" a scientist asked. Measurement of traces? "Impossible."

Measurement errors occur. Claims of absolute precision are not validated by independent authorities. False positives and negatives in lab results are not uncommon, scientists say.

A thermal cycler, the polymerase chain reaction (PCR) machine at the heart of the test for GM content, looks to the untrained eye like a simple fax machine. But its process of separating and fusing DNA to test for GM sequences is highly sophisticated.

The test routine involves scientists grinding food samples into fine particles, then turning the result into solvents in test tubes for DNA assessment in a spectrophotometer.

Tiny test tube samples are then slotted into the top of the thermal cycler where successive heating and cooling causes DNA samples to separate and come back together, before the ultimate visualization of the DNA in an ultraviolet transilluminator.

The final product is a DNA sequence which, when compared with the DNA reading from a scientific certified reference material (CRM), shows whether the GMs are present at the specified level.

A white dot on film for yes, no black dot for no.

But simply testing a food for GM ingredients is of limited use. "The proof of the pudding is whether informed people will care about a 'may contain' label," said one Australian scientist. "In the end it's all about acceptable risk."