New CRISPR-based COVID-19 test uses smartphone cameras to spot virus RNA

This one brings us closer to the Star Trek medical universe:

Scientists at UC Berkeley and Gladstone Institutes have developed a new CRISPR-based COVID-19 diagnostic test that, with the help of a smartphone camera, can provide a positive or negative result in 15 to 30 minutes. Unlike many other tests that are available, this test also gives an estimate of viral load, or the number of virus particles in a sample, which can help doctors monitor the progression of a COVID-19 infection and estimate how contagious a patient might be.

“Monitoring the course of a patient’s infection could help health care professionals estimate the stage of infection and predict, in real time, how long is likely needed for recovery and how long the individual should quarantine,” said Daniel Fletcher, a professor of bioengineering at Berkeley and one of the leaders of the study…

The new diagnostic test takes advantage of the CRISPR Cas13 protein, which directly binds and cleaves RNA segments. This eliminates the DNA conversion and amplification steps and greatly reduces the time needed to complete the analysis.

“One reason we’re excited about CRISPR-based diagnostics is the potential for quick, accurate results at the point of need,” [Jennifer] Doudna said. “This is especially helpful in places with limited access to testing or when frequent, rapid testing is needed. It could eliminate a lot of the bottlenecks we’ve seen with COVID-19.”

In the test, CRISPR Cas13 proteins are “programmed” to recognize segments of SARS-CoV-2 viral RNA and then combined with a probe that becomes fluorescent when cleaved. When the Cas13 proteins are activated by the viral RNA, they start to cleave the fluorescent probe. With the help of a handheld device, the resulting fluorescence can be measured by the smartphone camera. The rate at which the fluorescence becomes brighter is related to the number of virus particles in the sample.


Now that the CRISPR-based assay has been developed for SARS-CoV-2, it could be modified to detect RNA segments of other viral diseases, like the common cold, influenza or even human immunodeficiency virus. The team is currently working to package the test into a device that could be made available at clinics and other point-of-care settings and that one day could even be used in the home.

“The eventual goal is to have a personal device, like a mobile phone, that is able to detect a range of different viral infections and quickly determine whether you have a common cold or SARS-Cov-2 or influenza,” Fletcher said. “That possibility now exists, and further collaboration between engineers, biologists and clinicians is needed to make that a reality.”

I recall once asking Silvana Konermann: “What am I going to buy at the CRISPR store?”  Well, this is what you are going to buy at the CRISPR store.

Here is the article.  And funded by Fast Grants, I am happy to say.  Quite the week for science, yes?


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