Scientists from Oxford University have developed a test that detects and identifies viruses in less than five minutes, including coronavirus, using machine-learning software.
The new test is able to differentiate with high accuracy SARS-CoV-2, the virus responsible for the Covid-19 disease, from negative clinical samples, as well as from other common respiratory pathogens such as influenza and seasonal human coronaviruses.
It is similar to current tests that take throat swabs of potential Covid-19 patients. Although the results from most tests can take up to a couple of days, the new method is quicker because the sample doesn’t need to undergo genome extraction and the viruses don’t need to be purified or amplified to identify them.
Instead, the new procedure rapidly labels virus particles in the sample with short fluorescent DNA strands. A microscope is then used to collect images of the sample, with each image containing hundreds of fluorescently-labelled viruses.
Machine-learning software automatically identifies the virus present in the sample. Distinct virus types have differences in their fluorescence labelling due to variation in surface chemistry, size, and shape, which means they can be quickly identified.
The researchers aim to develop an integrated device to be used for testing in businesses, music venues, airports and other public spaces to establish and safeguard Covid-19-free areas.
Scientists are working with Oxford University Innovation (OUI) and two external business advisers in helping to mass-produce and distribute the tests. They are seeking investment to speed up the process, so the method can be used as a real-time diagnostic platform capable of detecting multiple virus threats.
The scientists have worked with clinical collaborators at the John Radcliffe Hospital in Oxford to validate the technique, which was confirmed by conventional RT-PCR (Reverse transcription polymerase chain reaction) methods. RT-PCR is a technique used in most Covid-19 tests, which combines reverse transcription of RNA into DNA and the amplification of specific DNA targets using polymerase chain reaction.
“Unlike other technologies that detect a delayed antibody response or that require expensive, tedious and time-consuming sample preparation, our method quickly detects intact virus particles; meaning the assay is simple, extremely rapid, and cost-effective,” Prof Achilles Kapanidis of Oxford University’s Department of Physics, which developed the test, said.
Scientists at the university hope the new technology can make mass testing a reality.
“A significant concern for the upcoming winter months is the unpredictable effects of co-circulation of SARS-CoV-2 with other seasonal respiratory viruses.
“We have shown that our assay can reliably distinguish between different viruses in clinical samples, a development that offers a crucial advantage in the next phase of the pandemic,” said Dr Nicole Robb of Warwick Medical School, said.
Last month, British Prime Minister Boris Johnson announced Operation Moonshot, a plan to expand testing from hundreds of thousands of tests each day to 10 million by early 2021, but doctors have said the programme is already in crisis.
The government has been under fire for not being quick enough to act on track and trace, as well as on mass testing.
NHS Providers, a body that represents the UK’s National Health Service, warned on Friday that several NHS trusts stood down in-house coronavirus testing for staff in the summer, ahead of a second wave of cases.
Despite assurances from the government about testing capacity, some staff in virus hotspots were then unable to access testing when the NHS came under strain earlier in the autumn.