Teddies Chemistry teacher helps develop COVID-19 testing
Chemistry teacher Dr Beth Watts has been seconded to the government’s flagship COVID-19 testing laboratory, where she has been applying the expertise she gained during her PhD to help increase the UK’s COVID-19 testing capacity.
The test she is involved in starts with a nasal swab which collects human cells and viral particles – if present. The swab is then sent to one of several labs now operating across the country. These samples are then added to a lysis solution which ‘kills’ any viruses, or makes them ‘inactive’. It is then safe to conduct the next part of the process outside of the biosafety cabinet. (see below)
The virus – named SARS-CoV-2 – has RNA as its genetic material. In order to be able to detect its presence and to distinguish it from human RNA it must first be purified, and then converted into DNA. An enzyme called Reverse Transcriptase is added to perform this job. Next, small pieces of fluorescently labelled-DNA (primers) are added to specifically bind to complementary regions of the viral genome. Another enzyme exponentially amplifies these regions. Finally, fluorescence emitted from the viral DNA is detected and measured using a real-time PCR machine.
Manual pipetting is currently limiting the team Dr. Watts is working in to about 5,000 tests per day, but the procedure is gradually being automated as more liquid handling robots are brought on site. Once programmed and verified, these robots will soon allow over 30,000 tests to take place daily. (a target approved by Health Secretary Matt Hancock when he visited the lab last week).
Dr. Watts says ‘I am very grateful to the school and my colleagues for allowing me to contribute to this national effort, especially because our ability to test widely will be central to our containment strategy once we have passed the peak of infections. I’m looking forward to seeing everyone again when the school physically reopens and I wish all my students the best in their learning in the virtual world.’