Right now, just one in 1000 cows that pass through the deathly gates of an industrial slaughterhouse is tested for harmful pathogens. That's because the current method for testing meat costs $50 and takes 12 hours. The consequences of this languorous process speak for themselves: 5000 Americans die from food-borne illness, while 76 million others -- one in four people in the country -- fall sick.
Everyone wants to blame food producers for these illnesses. But if anything, the recent spate of deadly food poisoning outbreaks highlights the huge variety of ways producers can make mistakes in food safety. It would be virtually impossible to eliminate infection from the food system altogether. The best solution, instead, may be to find a better way to test our food -- and a group of graduate students at the Yale School of Engineering and Applied Sciences thinks they've found the answer.
These budding engineers, led by Monika Weber and supervised by engineering Professor Mark Reed, have developed a design for a device that would cut the cost of testing down to $1, and the time it would take to test a sample down to 30 minutes. The design, which they call the α-screen (pronounced "alpha-screen") uses nanotechnology to detect the presence of bacteria so quickly and accurately that Weber says it may one day allow meat producers to incorporate bacterial testing into the production line and test every single cow that goes to market.
Weber told The Huffington Post that a prototype is still a year or so off, but the team's design was promising enough to take top honors at this year's NASA Tech Brief Engineering competition. It beat out 900 other designs from 50 countries for a $20,000 prize.
Under the meat testing process currently in place, samples of meat are taken from the meat factory to an external lab, where inspectors use a process called polymerase chain reactions (PCR) to test for the presence of potentially disease-causing bacteria. In order to get PCR to work, scientists have to have a large quantity of bacteria -- far larger than could ever be collected from a sample of meat. This means that scientists have to let the bacteria culture for hours before they can even begin PCR testing. This is old technology; both its reliability and its tediousness have been demonstrated by decades of lab work.
The new design relies on a combination of brand-new and time-tested technology. Samples of blood or other fluids from the animals being tested are inserted into the device, which Weber says will be around the size of a quarter. Once inside, the fluids are pumped into a separator, which divides the blood from the bacteria contained within. The bacteria are concentrated 1000 times and are then passed through nanowires (which Weber compared to the silicon pathways of a computer chip) that test for the presence of telltale "biomarkers" of harmful bacteria. The biomarkers -- chemical and electric codes specific to each organism -- interact with a "biological glue" affixed to the nanowires. Any interaction produces a change of current, which registers as a positive result on the device. The prize-winning design could be adapted to a test for any possible form of bacteria. E. coli, listeria and salmonella are the big names, but each one has dozens of strains, and many other common bacteria have been known to cause disease.
"If a customer wanted to test for a very large number of strains -- several hundred, say -- it would be possible to scale-up the device to accommodate that, of course," Weber told The Huffington Post.
Weber and her team are focusing on creating a working prototype, which they are confident they will be able to build within a year or two. They have already filed patents for the device, which they hope eventually to market for use in the food industry. Weber said the Tech Briefs prize has been a huge boost to the project's chances of success.
"The prize means a lot, and there has been huge publicity as a result," she said. "It's helped us get so much closer to getting the necessary support to build a prototype of the device -- and hopefully get it to the people who need it."
By "the people who need it," she means everyone who eats food from industrial producers. She means, in short, you.
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