When you deliver corn and soybeans this fall, elevators and processors will take your word about whether your bushels carry biotech genes.

But, perhaps as early as this winter, each load to the elevator may take about 20 minutes longer than usual. That's enough time for an elevator employee to run some type of quick lab test to tell whether you're delivering what the Europeans call a genetically modified organism (GMO).

Such a test won't be a question of your integrity as much as an attempt to catch honest mistakes that could cause a buyer to reject thousands of bushels.

Here's a roundup of the tests available at presstime. Recognize that the tests can identify only a single, specific trait at a time. That means running several tests to find what biotech genes, if any, are present. And each test will cost someone money.

Strategic Diagnostics Inc. (SDI), Newark, DE, and EnviroLogix Inc., Portland, ME, have dipstick test kits using immunoassay technology to identify the proteins associated with different bioengineered crops.

You insert a paper dipstick about 3" long and 1/4" wide into the test tube that contains a ground up seed and a chemical. Then you read the dipstick for positive or negative results. The 20-minute test costs about $3.50.

Seed companies have used an SDI dipstick to confirm the 98% purity of Roundup Ready cotton. SDI has developed tests for the seed industry to identify Bt and herbicide resistance genes and is adapting dipsticks for the grain trade.

The EnviroLogix dipstick tests, called QuickStix, can recognize the YieldGard Bt in corn kernels or the NatureGard and KnockOut Bt in leaf tissue. The company is working on test kits for other Bt types, too.

Iowa State University has a patent pending on a process that uses nearinfrared reflectance spectroscopy (NIRS) to identify Roundup Ready soybeans. The researchers are studying whether the test will identify other biotech genes as well.

Grain companies and processors can use a process called the polymerase chain reaction (PCR) to check for DNA. Genetic ID Inc., Fairfield, IA, is one of several companies with this sophisticated technology that can report the amount of GMO in raw and processed soybeans, corn and canola. The test takes two to three days and costs about $400.