It could be about to become much cheaper and easier to test for Ebola, thanks to a new identification method involving DNA-programmed blotting paper.
A group of scientists in the US were able to detect the virus after discs of paper were embedded with DNA and RNA fragments from jellyfish and other organisms.
The material was freeze-dried and preserved at room temperature, but when water was added it became reactivated. Once active, the paper changed colour if a particular target – such as a segment of Ebola viral RNA – was present in the water.
This is because the target fragment attached itself to a gene switch in the DNA, instigating the production of a colourful substance such as the protein that gives jellyfish their green glow under ultraviolet light or the bacterial proteins that produce visible colour changes. The colour the paper changed to revealed which of the target pathogens was present.
"We were surprised at how well these materials worked after being freeze dried," lead researcher Jim Collins told the BBC. "Once they're rehydrated, these biological circuits function in these small paper disks as if they were inside a living cell."
The results, published in the journal Cell, show how they were able to detect two strains of the virus in just 30 minutes, including the Zaire strain currently taking the lives of thousands of people in west Africa.
This was much faster than the speed of Ebola identification methods currently available. Not only that, but the whole test was conducted using an estimated $21 worth of materials – other tests are much more expensive than this.
The cost could be reduced even further if DNA circuits are made “in-house” instead, Collins explained to the New Scientist. “It's the order of pennies," he said. "The advantages we're bringing include low cost, no refrigeration needed and fast output.”
Over 10,000 people have been infected wit Ebola and almost 5,000 have died since the start of the outbreak in December last year, according to the latest figures from the World Health Organisation (WHO).
Earlier this month, the assistant director-general of the WHO warned that there could be as many as 10,000 new cases per week by December.