Scientists create rapid saliva test to identify Covid-19 variants

SAO PAULO – A group of scientists from Harvard Universities and the Massachusetts Institute of Technology (MIT) this week released a Covid-19 test platform capable of separating different variants of the virus faster, easier to transport and cheaper .

Diagnostic tests capable of separating different variants of the new coronavirus in samples from infected patients typically require genetic sequencing, which requires transporting samples to laboratories that have large, slow and costly operating machines.

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In a study published last Friday in the journal Science Advances, however, the researchers presented a saliva testing platform that can be mounted by a 3D printer at a cost of $15, capable of running tests for variants of Sars- CoV-2 priced at $6 a unit.

Scientists have not yet detailed how the technology will be licensed, but they say the idea is to make it available to as many monitoring centers as possible inside and outside the US, so that the spread of the Covid-19 concern variants is well mapped.

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Led by engineer Helena de Puig, the researchers describe in the study the motivation to create the new testing platform, named with the acronym miSHERLOCK (Minimally Instrumented Specific High-Sensitivity Enzymatic Reporter Unlocking).

“The Covid-19 pandemic highlighted the need for diagnoses that could be quickly adapted and used in different situations. Several variants of Sars-CoV-2 showed troubling effects on the efficacy of vaccines and treatments, but no portable test allowed for their identification” , write De Puig and his team in the article published by “Science Advances”.

Fruit of CRISPR

To create the test, the scientists used the CRISPR method for genetic manipulation, an invention that won the Nobel Prize in Medicine in 2019. one of the Covid-19 variants.

In the study, the researchers show that the platform was able to correctly identify the Alpha, Beta and Gamma variants of the coronavirus (originally detected in the UK, South Africa and Brazil). All of them proved to be more contagious than the coronavirus strain that emerged in 2019 in China. Scientists say they are already working for the test to also include the ability to differentiate the Delta variant (first found in India), the one that most concerns health authorities in the world today.

Diagnosis occurs through chemical reagents that respond to the presence of each of these virus strains in the sample. When a variant is present, the ampoule with the sample takes on a luminescent color. To interpret the result, the scientists created a mobile application that interprets the color of the exam with the camera, eliminating the need for specific machinery.

According to scientists, a saliva sample can be processed in just over an hour. In the test performed in the study, Covid-19 variants were correctly identified in 96% of the samples.

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