Oxford experts develop five-minute Covid-19 test

Scientists from the University of Oxford have developed what is described as “an extremely rapid diagnostic test” for that detects and identifies viruses in less than five minutes, which could potentially aid testing at airports and help revive the airline, tourism and other sectors.

The method, published on the preprint server MedRxiv, is able to differentiate with high accuracy SARS-CoV-2, the virus responsible for Covid-19, from negative clinical samples, as well as from other common respiratory pathogens such as influenza and seasonal human coronaviruses.

The university said on Thursday that working 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 test uses a convolutional neural network to classify microscopy images of single intact particles of different viruses.

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 conventional 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.”

The researchers aim to develop an integrated device that will eventually be used for testing in sites such as businesses, music venues, airports to establish and safeguard Covid-19-free spaces, the university added.