Simple test for E. coli.

Using technology developed privately, a USDA biochemist has developed a rapid, easy-to-use test that detects E. coli in food products. The test uses magnetic beads coated with anti-E. coli O157 antibodies and ruthenium-labeled antibodies. Ruthenium is a metal that, through a chemical reaction, emits light that helps detect the presence of E. coli.

USDA/ARS scientists (Plant-Soil Biophysics Research Unit, Eastern Regional Research Center, 600 E. Mermaid Lane, Wyndmoor, PA 19038) used equipment and technology patented by IGEN International Inc. (Gaithersburg, MD) to perfect the test. The test, for use on hamburger meat, is from 10 to 100 times more sensitive than other tests for E. coli.

ARS researchers developed the assay. No special training is necessary to conduct the inexpensive test. The equipment, including a computer, can fit on a small table. Samples can be loaded onto a tray similar to a carousel in a slide projector, and 50 samples can be tested in an hour. Total time from the start of the test to results is only 6 hr.

From the new assay, investigators are developing a line of fast, highly sensitive tests that will help detect contaminants. The company develops, manufactures and markets diagnostic systems using patented electrochemiluminescence technology, which is based on chemically-generated light that detects pathogens.

Further information. C. Gerald Crawford; phone: [phone]; fax: [phone]; email [e-mail].