New Simple, Inexpensive Test Accurately Detects E. Coli 0157By
Using technology developed by a private company, 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 0157
antibodies and ruthenium-labeled antibodies. Ruthenium is a metal that, through
a chemical reaction, emits light that helps detect the presence of E. coli.
C. Gerald Crawford, with USDA's Agricultural
Research Service, used equipment and technology patented by
IGEN International, Inc., of Gaithersburg,
Maryland, to perfect the test. The test, which works on hamburger meat, is from
10 to 100 times more sensitive than other tests for E. coli. Crawford
developed the assay at the ARS Eastern
Regional Research Center in Wyndmoor, Pennsylvania.
No special training is necessary to conduct the inexpensive test and the
equipment, including a computer, can fit on a small table. Samples can be
loaded onto a tray similar to a carousel for a slide projector, and 50 samples
can be tested in an hour. Total time from sample to answer: only 6-8 hours.
A large commercial meat supplier is evaluating the test. From the new
assay, IGEN hopes to develop a line of fast, highly sensitive tests that will
help food producers detect contaminants. IGEN develops, manufactures and
markets diagnostic systems using ORIGEN, patented "electrochemiluminescence"
technology, which is based on chemically generated light to detect pathogens.
Scientific contact: C. Gerald Crawford, Plant-Soil Biophysics
Research Unit, Eastern Regional Research Center, Wyndmoor, PA 19038; phone (215)
233-6628, fax (215) 233-6746, e-mail email@example.com.