Within about 30 minutes, and without ever going to a lab, a new paper tool can tell if someone has Ebola. The current test goes much slower and requires a lab and electricity. Using a new synthetic biology technique, researchers have eliminated all those concerns and made the pocket-sized test, which can be shipped anywhere in the world and stored without refrigeration. It’s both cheaper and much faster than any current Ebola tests.
“It’s a very inexpensive platform,” says professor James Collins, co-director of the Wyss Institute for Biologically Inspired Engineering at Harvard University, where a prototype of the new test was developed. “Each sensor costs only four cents to 65 cents to make.”
It’s also easy to understand. If someone has the disease, the paper changes from yellow to purple. It works by embedded components of a cell on the paper, and then programming those components to react if it detects the virus.
“You can basically take the machinery from within living cells–the molecules–in what’s called a cell-free extract,” Collins explains. “You can spot that onto paper, freeze-dry those spots, and then store and distribute the paper at room temperature as needed.”
The technology can last for months without refrigeration, a huge advantage in parts of the world where electricity is unreliable or nonexistent. When someone needs to use one of the strips, a few drops of water reactivate the molecules, and they start to function as if they’re in a living cell.
The technology can be programmed to respond to different inputs, so variations of the paper tool could also help diagnose other diseases.
“I think it informs a new class of programmable diagnostic tests,” says Collins. “You could envision using it also as a diagnostic for more complex diseases like cancer, where we can use the platform to detect the presence of certain micro-RNA that are indications of the presence of cancer.” Other tests could detect glucose levels in blood, or determine if an infection is resistant to antibiotics.
The platform itself will likely speed up the development of more new tests. The team at Wyss was able to create 24 different working sensors for Ebola in just 12 hours. Now, though those tests are just prototypes, they hope to work with others to bring a low-cost test to market for the current epidemic.
“We would like to participate and help out with the crisis in whatever way possible,” Collins says. “We’re keen to partner with other groups, particularly those that have good sample prep technology as well as experience developing diagnostic tests that can actually be distributed and used in the field. We would like to see this moved out as fast as possible.”