Saliva-based smartphone platform built for rapid COVID-19 testing

NY, Scientists have developed a saliva-based laptop smartphone platform for rapid Covid-19 test which they claim can provide results in 15 minutes without the resource-intensive lab tests.

The new technique detailed in the journal Science Advances pairs a fluorescence microscope reading device with a smartphone to determine viral load from a CRISPR / Cas12a assay.

The new test works as effectively as the well-established quantitative reverse transcriptase polymerase chain reaction method, experiments in a small number of participants showed.

“We believe this smartphone platform, a similar future application, offers the potential to rapidly expand Covid-19 detection capacity and potentially simplify contact tracing verification, to improve local containment and inform regional enforcement efforts. disease, “the authors wrote.

Most Covid-19 tests currently require rubbing the upper part of the throat behind the nose, an uncomfortable process that requires medical professionals in full protective gear to collect samples in isolation rooms from airborne infections before perform RT-PCR tests.

However, recent studies have found that SARS-CoV-2, the virus responsible for Covid-19, may be equally present in the nasopharynx and saliva during early infection, suggesting that evidence for Covid-19 based on saliva could allow for comparable reliability but simpler, safer testing.


To develop a widely accessible platform for saliva-based testing, Bo Ning from Tulane University School of Medicine in the US and colleagues built a prototype test chip that uses the CRISPR / Cas12a enzyme to enhance the signal. of an amplified viral RNA within a saliva sample.

They integrated the chip into a smartphone-based fluorescence microscope reading device, which captures and analyzes images to determine if the virus is present above a threshold concentration.

The researchers used this design to analyze the saliva of 12 Covid-19 patients and six healthy controls, and found that the approach successfully distinguished between patients with and without the virus.

In addition, the researchers compared nasal and saliva swabs from non-human primates before and after infection.

They found higher levels of SARS-CoV-2 RNA in saliva swabs, further suggesting that saliva may provide a robust means of diagnosis after infection.

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