Researchers got a step closer to developing an inexpensive rapid-result test that could detect deadly diseases such as Ebola.

These tests could be administered anywhere in the world without the need for a medical facility and would be contained on a pocket-sized paper diagnostic tool, Harvard's Wyss Institute for Biologically Inspired Engineering reported.

"In the last fifteen years, there have been exciting advances in synthetic biology," said Wyss Core Faculty Members James Collins. "But until now, researchers have been limited in their progress due to the complexity of biological systems and the challenges faced when trying to re-purpose them. Synthetic biology has been confined to the laboratory, operating within living cells or in liquid-solution test tubes."

The new process can be compared to computer programming; a synthetic gene network is built to carry out functions (similar to software applications) within a living cell, which can be thought of as the "operating system."

"What we have been able to do is to create an in vitro, sterile, abiotic operating system upon which we can rationally design synthetic, biological mechanisms to carry out specific functions," Collins said.

Once freeze dried these tests could be stored safely at room temperature for up to a year; to be activated they would only need to be rehydrated with water.

To prove the effectiveness of the concept the researchers demonstrated a variety of paper-based tools, from RNA actuation of genetic switches to programmable paper-based diagnostics that can detect Ebola in less than an hour.

The novel Ebola sensor employed a gene regulator called a "toehold switch," which boasts "unparalleled programmability and flexibility." The switch can be programmed to turn on gene expression in potential targets and detect almost any RNA signature. The resulting RNA-based organic nanodevice has a 40-fold better ability to control gene expression than conventional regulators.

"Whether used in vivo or in vitro, the ability to rationally design gene regulators opens many doors for increasingly complex synthetic biological circuits," said Wyss Institute Postdoctoral Fellow Alex Green.

The findings were published Oct. 23 in the journal Cell.