New paper based assay is capable of detecting the Zika virus within only a few hours.
The test, developed by a team from several different universities, utilises programmable genetic “switches” embedded onto paper discs to identify the virus. Cheap, simple to manufacture and storable at room temperature, the test can be used on a widespread basis in places with little medical infrastructure.
Riboregulators are synthetic genetic switches programmed to respond only when they detect a specific nucleic acid. By identifying 24 unique RNA sequences specific to the Zika virus, the team was able to create a set of switches for each sequence and freeze dry them onto a paper disc, which if it detects the virus, changes colour from yellow to purple. When assessing the accuracy of their solution, the team was surprised to find that the sensors could be activated by samples containing concentrations as low as two to three parts per quadrillion of Zika virus within hours.
Taking the utility of the test further, the team was able to utilise the CRISPR gene editing technique, on the same test paper, to identify and cut only the RNA of the American strain of the virus, allowing the team to specify the strain they want to detect, as the African strain is left uncut.
The team believe that, although there is still some way to go, their approach demonstrates the potential that the field of biomolecular diagnostics could contribute to combat crises such as the zika outbreak.