Lim Chwee Teck

Developing a PCR test that can yield results in an hour

Professor Lim Chwee Teck with the portable polymerase chain reaction kit called Epidax. ST PHOTO: DESMOND WEE
Professor Lim Chwee Teck with the portable polymerase chain reaction kit called Epidax. ST PHOTO: DESMOND WEE

Professor Lim Chwee Teck has spent the bulk of his career developing microfluidic biomedical devices, which analyse tiny amounts of fluids to detect diseases such as cancer. But when the Covid-19 crisis was rapidly worsening early this year, he switched to Covid-19 diagnostics.

"We felt we had to do something despite the fact that we had not worked on flu viruses previously," said Prof Lim, director of the National University of Singapore's Institute for Health Innovation & Technology.

Since March, he and his team have developed a portable polymerase chain reaction (PCR) diagnostic system that can produce test results within an hour, and he is currently developing an antigen rapid test kit that can detect Covid-19 within 15 minutes.

The portable PCR kit, called Epidax, uses a specially designed microfluidic chip to process a smaller amount of a nasal swab sample to detect Covid-19 faster.

A reagent is used to extract the ribonucleic acid (RNA) and amplify it on the chip so the PCR test can be done. "All these features significantly minimise sample handling and shorten the test and waiting time, so patients can get their test results in about an hour or less," said Prof Lim.

In conventional PCR tests, the nasal swabs are sent to a lab to extract the RNA before the test can be done. Those taking a conventional PCR test usually have to wait a day or two for their results.

So far, clinical tests with Epidax have shown 100 per cent accuracy in detecting Covid-19.

Prof Lim hopes that his faster and portable PCR system can be used for rapid screening and mass testing in places such as clinics, schools and offices.

The team has filed a patent for Epidax and licensed the technology to a local medical technology company.

A version of this article appeared in the print edition of The Straits Times on December 14, 2020, with the headline 'Developing a PCR test that can yield results in an hour'. Print Edition | Subscribe