DIY reagents for COVID-19 testing
20 May 2020
Researchers in Warwick Medical School at the University of Warwick have developed a way to create some of the more crucial reagents for use in COVID-19 tests. The DIY reagents might also enhance the use of, and production of, future tests.
The high demand for the reagents used in COVID-19 tests is creating supply issues in the UK and, even greater issues across developing countries. So, a team of University of Warwick researchers decided to try to make more of the enzymes needed to produce reagents themselves, using Warwick Medical School's laboratories. They aimed for results that could then be recreated for use in commercially available testing kits.
Not only did the team succeed in producing those crucial and much sought-after enzymes to bolster production of testing kits, they may also have found ways that could extend and simplify the way those reagents are used in COVID-19 tests.
The team produced a package of key enzymes:
- A Reverse transcriptase (an enzyme used to generate DNA from an RNA template)
- A Taq polymerase
- An RNAse inhibitor (also known as RNAsin)
- rTth; a hybrid enzyme with reverse transcriptase and DNA polymerase activities
They then provided these reagents to laboratories in two UK hospitals, who were able to validate their effectiveness in the creation of more Covid-19 testing kits. The same materials have also been sent to the Africa Centres for Disease Control and Prevention (Africa CDC) where the need for more reagents is even more pressing.
The Warwick research team's work may also provide opportunities to enhance current commercial tests, extending the range of temperatures they can be used at, and perhaps even simplifying future production.
Professor Mohan K. Balasubramanian, who is leading this work alongside Professor Karuna Sampath, said: "The commercial providers of the reagents and enzymes have themselves found and described eight interesting mutations to their reverse transcriptase, but to our knowledge they had not yet all been combined in the same molecule. We have now done that and found that that this actually improves the enzyme's activity across a wide range of temperatures."
"We have also made two further useful enzymes that would support the production of more reagents for Covid-19 testing. In particular a Taq-related polymerase (rTth polymerase), which itself has the reverse transcriptase activity which would greatly simplify the reagent production process and also render the reagent directly applicable in a single-step test."
