Singapore-MIT Alliance for Research and Technology (SMART), MIT’s research enterprise in Singapore, has received a grant from the National Medical Research Council (NMRC) COVID-19 Research fund for the acceleration of research and development of rapid paper-based serological and diagnostic tests for COVID-19.

WHY IT MATTERS

Although dozens of diagnostic tests, based on RNA or antibody detection, for COVID-19 have been made available, major challenges still persist. Current diagnostic tests require health workers with substantial Personal Protective Equipment (PPE) to collect swabs. Subsequently, skilled personnel and specialty laboratory facilities are needed to prepare samples, run assays, and detect assay signals. 

This restricts diagnostic capabilities to hospitals and specialized diagnostic laboratories. In addition, assay times for existing genomic profile and serological tests can take as long as 3 hours to 5 days. False negatives are also often observed in genomic profile tests due to low viral loads from throat swab samples. 

HOW IT WORKS

Researchers from SMART’s Antimicrobial Resistance (AMR) Interdisciplinary Research Group (IRG), Nanyang Technological University (NTU), and Massachusetts Institute of Technology (MIT) are working collaboratively to develop a rapid serological test and a rapid diagnostic test (RDT), based on protein detection, that could be used outside of laboratories, without specialized equipment or infrastructure, at places such as airports and community clinics.

Tests can be easily administered by anyone and will be stable in field conditions with results expected within 10 minutes. When SARS-CoV-2 virus is detected on the paper-based tests, the strips will change from white to blue to indicate positive for COVID-19.

For the paper-based serological test, S protein will be used to detect SARS-CoV-2 antibodies from blood or serum samples. S protein, which is much smaller than an antibody, allows for high-density capture of antigens. Cellulose offers fast flow rates and low non-specific binding, yielding greater sensitivity and faster testing at a lower cost than standard polystyrene 96 well plate serological tests. With the ability to detect past and active infections, the test will help determine the realistic number of SARS-CoV-2 infected cases to understand the true magnitude of the pandemic.

The paper-based RDT or biomarker test will be using S & N protein to detect SARS-CoV-2 biomarkers from swabs or bodily fluids such as saliva or blood. The ability to test for N protein, which is observed from as early as day 1 of disease onset, means that the RDT may be able to perform first-line screening for the virus, even for mild infections - an important feature that can help speed up containment efforts.

THE LARGER TREND

Last week, Singapore’s Duke-NUS Medical School, GenScript Biotech and the Diagnostics Development Hub (DxD) at Singapore’s Agency for Science, Technology and Research (A*STAR) announced a first of its kind COVID-19 serological test that allows rapid detection of neutralizing antibodies (NAbs) – the specific antibodies present in the serum of COVID-19 patients that are responsible for clearing the viral infection, without the need of live biological materials and biocontainment facility, MobiHealthNews reported.

UPCOMING DEVELOPMENTS

The next phase of the research will focus on the optimization of fusion proteins that enable high-performance paper-based immunoassays, the directed evolution of binding proteins, and the evaluation of both serology and viral protein tests using clinical samples. Broader usage and implementation of both tests are also being explored.

ON THE RECORD

“Testing of the SARS-CoV-2 virus is important to complement efforts in the fight against the COVID-19 pandemic. We are developing protein tests that may overcome existing challenges faced in Singapore and countries worldwide. These tests could be used by anyone, anywhere, with an almost immediate turnaround time for results. Think rapid influenza test kits but for COVID-19, the paper-based tests will change from white to blue when molecules of the SARS-CoV-2 virus are detected from bodily fluids such as the saliva,” said Professor Peter Preiser, Associate Vice-President for Biomedical and Life Sciences at NTU, and Co-Lead Principal Investigator at SMART AMR.