When news of COVID-19 making people ill in China broke in January 2020, a team of scientists under the HTX Chemical, Biological, Radiological, Nuclear and Explosive (CBRNE) Centre of Expertise, leapt into action to develop a test kit that can detect the virus at the borders, quickly and accurately, to prevent infected travellers from coming in to Singapore.
Developing the Test Kit
When the COVID-19 genome sequence information was published on the Global Initiative on Sharing All Influenza Data (GISAID), a global platform that enables rapid sharing of influenza virus data, the HTX scientists started working on the design of primers to develop a COVID-19 test kit. A primer is a short piece of DNA created to amplify a specific region of the target pathogen for identification using the Polymerase Chain Reaction (PCR) process.
The design of the primers is critical to ensure that the test kit is able to detect COVID-19 with high specificity and sensitivity, similar to how a key with a specific design will be able to open the corresponding lock. The scientists also incorporated degenerate primers to cover possible mutations of COVID-19.
These primers will be loaded on a Lab-on-Chip platform for tests to run. HTX collaborated with Veredus Laboratories, a company that specialises in developing molecular diagnostic solutions and patented the Lab-on-Chip platform. This platform integrates two molecular biological applications, Polymerase Chain Reaction (PCR) and microarray.
How it Works
The testing process involves extraction, amplification and analysis. The RNA of the samples are first extracted in the laboratory, and then loaded on a chip. These chips are then processed and results will be available.
Using this platform, we are able to process individual samples instead of doing batch-processing. This allows results to be delivered quickly, so that infected persons can be informed and contact tracing be conducted as soon as possible. This enables us to limit the spread of imported cases.
Deployment of the Test Kit
From 2359h on 4 Mar 2020, travellers entering Singapore who are deemed to exhibit symptoms such as fever and respiratory illness are required to undergo a nasal and throat swab. The swab samples are brought to the HTX laboratory for screening.
3-in-1 Test Kit
The HTX test kit can also test for two diseases with just one sample – COVID-19 and SARS-CoV. In the future, it will also be able to test for the Middle East Respiratory Syndrome Coronavirus (MERS-CoV).