Researchers at Northwestern University have created a new antibody test that detects antibodies to SARS-CoV-2, the virus that causes COVID-19. The minimally invasive test only requires a single drop of blood from a finger prick.

Antibody tests are useful in determining if someone has had prior exposure to a virus. It does this by detecting the presence of IgM and IgG antibodies that the body makes when infected with foreign viral proteins.

Currently, there are limited antibody tests that are quick and reliable without requiring blood from a vein. The antibody test being studied at Northwestern was developed in hopes of filling that gap in testing.

In their test, drops of whole blood collected from a finger stick are stored and dried on a special filter paper. The blood is then tested using a method called enzyme-linked immunosorbent assay (ELISA) to see if it contains antibodies to certain SARS-CoV-2 proteins that cause a strong reaction from our body's immune system.

So far, the finger prick testing has had promising results compared against traditional blood sampling.

The team now plans to test additional samples to determine exactly how well their antibody tests work. In addition, the research team is building a web-based platform to increase antibody testing across Chicago.

Widespread testing using this finger prick method would also mean people could take their own blood samples at home and send them to a lab through the mail. "By not requiring people to come into the clinic to have their blood drawn, we conserve clinical resources, keep people safe at home during shelter-in-place and greatly increase the potential reach of antibody testing," says Thomas McDade, Ph.D., a biological anthropologist in the Weinberg College of Arts and Sciences and lead author of the research paper, in a press release.

The team's article is now available on MedRxiv.

Read more about the test.