An imaging technique pioneered by Berkeley Lab is helping reveal the best antibodies to test for in rapid and reliable COVID-19 detection. Although current tests such as polymerase chain reaction (PCR) are highly accurate, these samples must be sent to an accredited lab for testing, causing a longer wait time for results. Michal Hammel, a research scientist in the Molecular Biophysics and Integrated Bioimaging Division, and Curtis D. Hodge, a former postdoctoral scholar, led a study that could help get reliable, self-administered tests with near-instant results on the market.
Hammel, Hodge, and their colleagues used small angle X-ray scattering (SAXS) performed at Berkeley Lab’s Advanced Light Source to examine about 20 antibody-antigen interactions. Their data showed that a highly sensitive lateral flow assay – the same type of device used in home pregnancy tests – could be developed using pairs of rigid antibodies that bind to the SARS-CoV-2 nucleocapsid protein. Such a test would only require a small drop of mucus or saliva, could give results in 15 minutes, and could detect a COVID-19 infection one day before the onset of symptoms. Their work was published in the journal mABs.
Antibody networking and high binding stability are known to improve the sensitivity of lateral flow assays, and researchers have long speculated that antibody flexibility plays a role in both properties. But studying the physical dynamics of antibody-antigen pairs to find the most effective antibodies is very difficult with traditional imaging techniques, which require the molecules to be stabilized or crystallized. The SAXS technique developed by Hammel and his colleagues allows scientists to examine antibodies and antigens in their natural state, i.e. when moving freely in a liquid.
The team is now investigating methods of improving test sensitivity even further.
Read more in the Berkeley Lab News Center.