Authors: Martha Powell, Future Science Group
The gene-editing technique CRISPR could be used to detect infections, potentially revolutionizing the diagnosis of viruses such as HPV and Zika, according to two papers recently published in Science.
The CRISPR-Cas system has previously been harnessed for genome editing, but in this new research it is demonstrated that the enzyme could be harnessed for the detection of a variety of infectious diseases.
The two CRISPR-based tests have been developed independently, one by Jennifer Doudna and her team at the University of California Berkley (CA, USA) and the other at the Broad Institute (MT, USA) by Feng Zhang and his team.
In the first paper, Doudna’s team describes the system they’ve developed, termed DETECTR, which can distinguish between highly similar strains of HPV. The team used CRISPR-Cas12a, demonstrating that this RNA-guided enzyme allowed unselective single-stranded DNA cleavage. When targeted to HPV DNA, and coupled with a reporter molecule, this enzyme was demonstrated to successfully signal cells infected with the virus, with the method achieving attomolar sensitivity for DNA detection.
In the second paper, Feng Zheng and his colleagues report an upgraded version of SHERLOCK, a technology combining isothermal pre-amplification with Cas13 to detect single molecules of RNA or DNA, which last year was demonstrated to be able to detect viruses such as Zika and dengue.
In the latest paper the team have improved the sensitivity of the technology and have developed paper test strips to display results, a beneficial feature for use in the field.
Both diagnostics require more development, however, in low-resource settings method, could these methods revolutionize diagnosis?
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Sources: Chen JS, Ma E, Harrignton LB. CRISPR-Cas12a target binding unleashes indiscriminate single-stranded DNase activity. Science doi:10.1126/science.aar6245 (Epub ahead of print); Gootenberg JS, Abudayyeh OO, Kellner MJ, Joung J, Collins JJ, Zhang F. Multiplexed and portable nucleic acid detection platform with Cas13, Cas12a, and Csm6. Science doi:10.1126/science.aaq0179 (Epub ahead of print)