By Dustin Renwick
Innovation has two parts: the awe-striking changes that generate instant headlines and the long-developing back stories. Products and processes that alter our world don’t happen in a flash. They are the results of years of research and open-minded collaboration that eventually meet in a more famous eureka moment.
Remembering the innovation is easier than remembering the story behind it.
EPA microbiologist Jennifer Cashdollar and her Pathfinder Innovation Project team are working on a fundamental shift in how we test for pathogens in water.
Currently, researchers use two main methods to detect viruses in water samples: culture-based and molecular.
Culture-based tests rely on living cells. If a water sample causes the cell culture to die, there’s a good chance that the sample contains an infectious virus, Cashdollar says. But this testing can be slow, and you’ll have a hard time processing cell cultures in the field.
Molecular tests identify viral genetic signatures in the water—nucleic acids, more commonly known as DNA or RNA. Such tests are less expensive, and could fit in a hand-held device. However, the identification of nucleic acids doesn’t always mean that a potentially infectious virus is in the water. Virus particles must be whole to be infectious, whereas fragments of floating DNA or RNA might register in the water samples but can’t affect humans.
“We’re trying to figure out how we can fill that gap between the culture and molecular methods,” Cashdollar says.
To do that, Cashdollar and her research partners are applying traditional techniques with an innovative twist.
If the team can show that traditional measurement techniques don’t allow nucleic acid fragments to pass through, any molecular signals in the final water samples would almost certainly originate from whole viral particles—which could be infectious because they’re in one piece.
The scientists have experimented with tap water so far, and they’ll soon test river water, a better real-world proxy. On the horizon, this work could lead to a field-ready device that not only gives the best of both detection methods, but also adheres to a classic story of innovation.
About the author: Dustin Renwick works as part of the innovation team in the EPA Office of Research and Development.