“We’re making molecular diagnostics as easy as a pregnancy test.” So says Ben Pascal, co-founder of a startup called Invisible Sentinel that makes a handheld DNA tester. One of the technology’s first applications is food safety: Put a prepared sample of peanut butter on the tester, and you’ll see one line if it’s safe, and two lines if there’s salmonella.
For food producers, the technology could mean much faster testing–and avoiding food waste while waiting for results from a lab.
Right now, some producers send samples to labs that use traditional microbiology. “There’s nothing wrong with that, except it takes someone fairly skilled to interpret those results, and it takes a while,” says Pascal. “And food’s perishable. If it takes a week or longer to get results, it might have spoiled by then, or you lost your shelf life.”
Rapid diagnostics–the type of DNA testing that the new tester provides–are becoming more common, but still usually involve sending samples to a lab and waiting two or three days for a result. They’re also expensive. By making testing cheap and simple enough to do on-site, the new device saves valuable time.
“If you’re producing, you can get results back the next day, and then you’re able to ship your product–that 24-48 hours is important, especially with the kind of volume you need to produce because your margins are slim in the food industry.”
It’s not quite as simple as putting a bit of food on the tester; someone has to prepare the sample first in an incubator and then raise and lower the temperature in another device. In other words, you’re not going to be doing this at home. But it’s still easy enough that anyone can do it with basic training.
“There are other molecular technologies out there that are really complicated and expensive, but we’ve been able to get in the door with customers and get up and running with something that’s faster, and anyone can understand,” Pascal says.
The results are also more reliable than traditional methods of plating at a lab. “When you’re able to detect DNA, there are some inherent advantages. You are much more accurate–less false negatives, less false positives, gives you more confidence in your results,” he says. “Because you’re only looking for DNA to recognize, you’re inherently more sensitive.”
That accuracy could also help prevent even more food waste–if there’s a false food safety scare, food often ends up in the trash. In 2008, there was a warning of salmonella in tomatoes that later turned out to be false. So many people stopped buying tomatoes that 32% of the total crop in the U.S. went unharvested.
The device is already in use with a wide range of foods, including meat, vegetables, and even candy. It can also be used for different applications, like testing the quality of beer or wine, or testing for health care or at vet clinics.