Australian Researchers Develop 20-Minute COVID-19 Antibody Test
Researchers at Australia’s Monash University have developed a test for SARS-CoV-2, the virus that causes COVID-19, that can provide results in 20 minutes. The research group was led by BioPRIA and Monash’s Chemical Engineering Department, and included scientists from the ARC Centre of Excellence in Convergent BioNano Science and Technology (CBNS).
The test can use 25 microliters of plasma from blood samples and is a simple agglutination assay. It is used to detect antibodies in response to SARS-CoV-2 infection. This is, as mentioned, an antibody test, which evaluates whether the individual had already had COVID-19. The more current swab/PCR tests evaluate if someone is currently positive with the disease, whereas an antibody test determines if someone already had the disease.
The test could be very effective in contact tracing. Using a straightforward laboratory setup, it could potentially test up to 200 blood samples per hour. And in laboratories with automated equipment, could potentially test 700 blood samples per hour, or in an ideal world, 16,800 per day. However, it’s unlikely most automated equipment could run nonstop, 24 hours a day.
The research was published in the journal ACS Sensors. The researchers have filed a patent and are looking for commercial and government support for upscale production.
“Detection of antibodies in patient plasma or serum involves pipetting a mixture of reagent red blood cells (RRBCs) and antibody-containing serum/plasma onto a gel card containing separation media, incubating the card for five to 15 minutes, and using a centrifuge to separate agglutinated cells from free cells,” said Simon Corrie, Senior Lecturer in Chemical Engineering at Monash and chief investigator in the CBNS. “This simple assay, based on commonly used blood typing infrastructure and already manufactured at scale, can be rolled out rapidly across Australia and beyond. This test can be used in any lab that has blood typing infrastructure, which is extremely common across the world.”
The authors wrote, “Short-term applications include rapid case identification and contract tracing to limit viral spread, while population screening to determine the extent of viral infection across communities is a longer-term need. Assays developed to address these needs should match the ASSURED criteria.”
ASSURED criteria are set by the World Health Organization (WHO) for the selection of diagnostic tests. ASSURED stands for Affordable, Sensitive, Specific, User-friendly, Rapid and robust, Equipment-free and Deliverable to end-users.
The WHO notes that these are benchmarks, but they are generic and need to be adapted to each diagnostic need. Also, not all tests can be simplified to fit the ASSURED criteria.
“We found that by producing bioconjugates of anti-D-IgG and peptides from SARS-CoV-2 spike protein, and immobilizing these to RRBCs, selective agglutination in gel cards was observed in the plasma collected from patients recently infected with SARS-COV-2 in comparison to healthy plasma and negative controls,” said Gil Garnier, director of BioPRIA. “Importantly, negative control reactions involving either SARS-CoV-2-negative samples, or RRBCs and SARS-CoV-2-positive samples without bioconjugates, all revealed no agglutination behavior.”
Banaszak Holl, with BioPRIA and Monash, added, “This simple, rapid, and easily scalable approach has immediate application in SARS-CoV-2 serological testing, and is a useful platform for assay development beyond the COVID-19 pandemic. We are indebted to the work of our PhD students in bringing this to life. Funding is required in order to perform full clinical evaluation across many samples and sites. With commercial support, we can begin to manufacture and roll out this assay to the communities that need it. This can take as little as six months depending on the support we receive.”