Researchers working out of Harvard and Boston University have developed a novel method of testing for infections. The technique is not only cheap (it uses less than $20 worth of materials), but it’s also durable, long-lasting and can detect infections in as little as 30 minutes.

“It’s a pragmatic, very big-deal improvement,” says Julius Lucks, an assistant professor of chemical and biological engineering at Cornell University. “Now we can ask ‘What do we want to do [with it]?’ ”

The breakthrough, it turns out, was embedding stem cells onto porous paper. That’s what separates the new tests from, say, traditional pregnancy tests – they relied on old-fashioned chemistry, while the new tests search for specifically engineered genetic reactions.

Once freeze-dried onto the paper, the tests work by detecting when an infection’s genetic materiel completes a “circuit,” of sorts. For instance Ebola, which has genetic material consisting of RNA, completes the circuit and causes the production of a protein that turns the paper dark purple within an hour.

While the strips still require some expertise for proper administration, they’re extremely cheap – a little as four cents per strip, and they can be designed and manufactured within a day.

Beyond the straightforward infection test, the technology opens up a whole host of possibilities – bandages could change color to warn of a developing infection, and even clothing could serve as an early signal for potential diseases. With the current Ebola scare, a cheap, fast diagnostic would be extremely valuable to health professionals.