Oxford scientists develop 5-min Covid-19 test
Scientists from the University of Oxford have developed what is described as “an extremely rapid diagnostic test” that detects and identifies viruses in less than five minutes, which could potentially aid testing for Covid-19 at airports and help revive the airline, tourism and other sectors.
The method is able to detect the coronavirus and differentiate it from other viruses with high accuracy, the researchers said in a preprint study published on the server MedRxiv.
The university said on Thursday that the method works directly on throat swabs from Covid-19 patients, without the need for genome extraction, purification or amplification of the viruses. The method starts with the rapid labelling of 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 quickly and automatically identifies the virus present in the sample.
The scientists hope to start product development in early 2021, and have an approved device available within six months of that time.
This approach exploits the fact that distinct virus types have differences in their fluorescence labelling due to differences in their surface chemistry, size, and shape, the university said.
The scientists worked with clinical collaborators at the John Radcliffe Hospital in Oxford to validate the assay on Covid-19 patient samples, which were confirmed by RT-PCR methods.
Achilles Kapanidis of the department of physics said, “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.”
In another development, a group of 80 researchers warned that the “herd immunity” approach to managing Covid-19 is “a dangerous fallacy unsupported by the scientific evidence”.
The warning is included in an open letter published by The Lancet and signed by top international researchers.