Nobel Doudna's new rapid test tracks down the coronavirus in just 5 minutes

If it confirms its performance, the new test will considerably reduce analysis times while quantifying the viral load at the same time

(photo: Getty Images) The new Nobel thanks to Crispr Jennifer Doudna, who together Emmanuelle Charpentier has just won the 2020 chemistry award precisely for the development of the DNA editing method, she also puts a hand in coronavirus diagnostics. His team has developed a new rapid test that, using Crispr, is able to identify the genetic material of Sars-Cov-2 in biological samples in a few minutes, without the need for many reagents and complicated machinery. And it also provides an indication of the viral load.

Crispr against coronavirus

Tests to detect coronavirus based on the Crispr-Cas methodology are nothing new in this pandemic. Basically they work like this: a complementary guide rna is created to a specific sequence of the viral genome; when the guide RNA pairs with the RNA of the virus it activates the Cas protein that cuts all those sequences by triggering a particular molecule which, hit by a laser pulse, emits a fluorescent signal.

Not bad, but for to be sure to find the genome of the virus until now we had to amplify it - an operation that does not significantly reduce the time compared to the classic swab test and does not even solve the problem related to the availability of reagents.

The new rapid test

This new test, on the other hand, has the fact that it uses more guides to increase sensitivity. In practice, the researchers explain in the preprint available on medRxiv, there is no need to amplify the genetic material of the virus because by making several guide rna work in tandem, it is possible to identify the virus even at low concentrations. If a guide rna works with 100,000 viral particles per microliter of solution, two guide rnas identify a positive sample with 100 viral particles per microliter.

As Melanie Ott, coordinator of the study with Doudna, reports to Science Magazine the sensitivity of the conventional molecular test (which also detects 1 viral particle per microliter) is reached, but the result is obtained in just 5 minutes.

The new test would also have another advantage: by not amplifying the quantity genetic material of the virus in the sample is not altered, giving the possibility to estimate the amount of virus present. Researchers, in fact, claim that the intensity of the fluorescent signal is proportional to the viral load when a sample is positive.

The rapid test with Crispr has not yet passed the scrutiny of the scientific community, but, if it is confirmed valid, it could reach commercialization very quickly