With this reaction, a glucose meter can detect SARS-CoV-2 antibodies in patient samples (Ab=antibody; Inv=invertase). (Credit: Journal of the American Chemical Society)

A simple and accurate glucose-meter-based test incorporates a novel fusion protein could someday be used to monitor SARS-CoV-2 antibody levels. Glucose meters are readily available and easy to use, and they can be integrated with remote clinical services. Researchers have been adapting these devices to sense other target molecules, coupling detection with glucose production.

The researchers designed and produced a novel fusion protein containing both invertase and a mouse antibody that binds to human immunoglobulin (IgG) antibodies. They showed that the fusion protein bound to human IgGs and successfully produced glucose from sucrose. Next, the team made test strips with the SARS-CoV-2 spike protein on them. When dipped in COVID-19 patient samples, the patients’ SARS-CoV-2 antibodies bound to the spike protein.

Adding the invertase/IgG fusion protein, then sucrose, led to the production of glucose, which could be detected by a glucose meter. They validated the test by performing the analysis with glucose meters on a variety of patient samples and found that the new assay worked as well as four different ELISAs. The researchers say that the method can also be adapted to test for SARS-CoV-2 variants and other infectious diseases.

For more information, visit here .