Researchers at Iowa State University say they’ve found a relatively simple way to use light to check livestock for certain neurological diseases — with one goal of the project being a fast, easy test for mad cow disease. I.S.U. chemist Jake Petrich says they’ve discovered the eyes of infected animals have an intense white “glow” when a special blue fluorescent light is shined on them.
“The difficulty is making the live animal sit still for five seconds without blinking its eye or jiggling around,” Petrich says. “Probably, it’s more practical to do the test in the packing plant immediately after slaughter.” The light test has been performed with the eyes of dozens of sheep, some of which were infected with scrapie (SCRAPE-ee), a neurological disorder similar to mad cow disease. Petrich says their discovery of this “glow” in infected animals has the potential for global implications.
“We’re searching for funding to make a device that we could put in the field,” Petrich says. “Right now our work is performed entirely with eyeballs, not with animals. We’d like to develop a device we could take into a packing plant and actually test there.” Anyone who watches TV crime scene investigation shows has likely seen police use a light wand in a darkened room when searching for certain types of evidence.
Petrich says they’d ideally like to go with something similar that could be handheld. “A wand is a nice compact way to make this but I’m not sure if it would be that easy to put all of the instrumentation into something that small,” Petrich says. “An easier way to do this would probably be to modify something, the kind of device you would have in your eye doctor’s office when he checks you for glaucoma.” The project was supported by a grant from the U.S. Department of Defense and the findings were published in the journal Analytical Chemistry.
