There are many problems with the current swab testing for coronavirus: they’re slow, easily contaminated, and many tests are inconclusive. Could the gene editing technique CRISPR be the answer to these problems?
The current method of testing uses PCR (Polymerase Chain Reaction) to amplify swab tests in the lab. For PCR to work it must be placed in a thermocycler where the DNA is repeatedly heated and cooled to 4 different temperatures. The equipment and manpower needed for this process racks up the time and costs of testing, whilst PCR itself is a timely process. Whereas the technique known as CRISPR (Clustered Regularly Interspaced Palindromic Repeats) effectively works as a pair of molecular scissors, using a specific restriction enzyme to cut at the desired section of DNA in order to alter it. CRISPR specialist, Mammoth, has partnered with GSK to develop the CRISPR method of testing that does not require a lab or technician. Hence making Covid-19 testing a much faster and cheaper process whilst reducing the heavy backlog of tests currently burdening labs.
The technique works by pairing an enzyme with an RNA guide that looks similar to coronavirus, which is able to detect the viral Covid-19 RNA in the sample. In addition to having this guide RNA, the test will also contain a reporting strand. When the RNA guide and enzyme is introduced to a sample that is Covid-19 positive, it pairs with the viral RNA. The enzyme then digests the whole strand, including the reporting strand. This reporting strand would be connected to a pregnancy-style test to give a clear positive or negative result, in as little as 20 minutes.
Initially, the CRISPR method will be used in labs, but with the potential of having a test that you can do yourself at home by the end of the year. But the benefits of this new test don’t stop there… If the CRISPR test works for detecting Covid-19, then it should work to test for other viruses as well. Going into flu season, if the right authorisation were granted, the CRISPR method could be utilised to create a dual test that delineates whether the subject presenting symptoms tests positive for Covid-19 or influenza. This would save flu patients unnecessary self-quarantine out of fear of spreading Covid-19.
By Ella Spittall
Header image: Fernando Zhiminaicela/Pixabay