GMO U.S. Grain Tests Still Seeking 'Magic Bullet'
Reuters Online Service
Mittwoch, 16. August 2000 17:14:00
Copyright 2000 Reuters Ltd. All rights reserved.@bThe following news report may not be republished or redistributed, in whole or in part, without the prior written consent of Reuters Ltd.
By Julie Ingwersen
CHICAGO (Reuters) - Genetically modified crops such as corn
and soybeans have gained fast acceptance in the U.S. grain
market in just a few years -- faster than the means to track
the crops through the food chain.
U.S. exporters want to meet the demands of customers in
Europe and elsewhere who want their grain free of genetically
modified (GMO) organisms.
But traders and analysts agree that the current means of
testing for GMO content are imperfect. Experts also say there
is no "magic bullet" test to certify the absolute absence of
GMOs.
"There's clearly a need to have a single test that would
give us accurate, affordable and timely results, but right now
there really isn't one single test that does that," Thomas
O'Connor of the National Grain and Feed Association said.
Moreover, even as scientists try to develop the "magic
bullet" to detect GMO traits, the booming biotech industry is
posing new challenges to test makers by developing even more
seed varieties, some with multiple genes "stacked" together.
DIPSTICK TEST
Currently, grain merchants who want to know -- and certify
-- what's in their bins have to choose between simple portable
test kits that generally check for only a single genetic trait
at a time, or a type of DNA analysis called PCR that provides
more information but costs more and takes several days.
The simplest "dipstick" tests check for the presence of a
protein expressed by a particular gene. Users crush a small
sample of grain -- for corn, about 50 to 60 kernels -- and mix
it with water, then dip a treated test strip in the solution.
After a few minutes, either one or two dark lines appear on
the strip, depending on the presence of the protein.
At a cost of less than $10 per test, manufacturers say such
kits are popular among operators of small grain elevators and
others who need quick information to make marketing decisions.
Nicholas Phillips, of Delaware-based test maker Strategic
Diagnostics Inc. (SDIX.O), said that while the strip tests may
not provide a thorough analysis, "It's enough for the risk
management decisions to be made."
But because the strip tests are so specific, it helps to
know what to look for. Phillips said SDI collects information
on what GMO crops are grown where, so elevator operators have a
rough idea of which tests they will need.
DNA TESTS $450 A SHOT
Far more sensitive than strip tests is the process known as
polymerase chain reaction, or PCR, which analyzes a crop's
actual DNA. PCR requires a larger grain sample of at least 5 or
6 pounds of soybeans or corn.
The sample is taken to a laboratory at a typical cost of
about $200 to $450 per test, according to the U.S. Department
of Agriculture's Economic Research Service. Results are
available in two to 10 days.
How practical that is for grain traders needing to handle a
record 10 billion bushels of corn and three billion bushels of
soybeans this autumn at harvest remains to be seen.
But PCR can quantify the GMO content in a grain sample and
can detect the presence of several traits in a single test. One
U.S. testing company, Genetic ID Inc. of Fairfield, Iowa,
claims its technology can detect as little as two molecules of
DNA.
Genetic ID spokesman Jeffrey Smith says that unlike the
dipstick tests, PCR also works on many processed foods. He said
his company's clients include food ingredient suppliers,
manufacturers and large farmer cooperatives, among others.
Genetic ID announced last week that all of its testing
methods for GMOs had been accredited by the United Kingdom
Accreditation Service, an independent organization that has
multilateral agreements with counties on five continents.
LOOKING TO THE USDA
The USDA outlined plans in May to begin evaluating test
kits and accrediting laboratories that perform GMO detection.
The agency said it plans to open a reference laboratory for
the effort in Kansas City, Missouri, by the end of the year.
Those steps were welcomed by Leah Porter of the American
Crop Protection Association. She says the ACPA, whose members
include biotech companies, is concerned about the accuracy of
some of the test kits out on the market.
"You have to realize the kit is only as good as the
reference material that it was developed from," she said.
"That's why we're very encouraged by what the USDA is doing
with validation programs. You're talking about some high-volume
products being moved from the United States to other markets,
and there's a lot riding on the potential for false negatives
or positives."