Working around the clock for two weeks, a large team of Stanford Medicine scientists has developed a test to detect antibodies against the novel coronavirus, SARS-CoV-2, in blood samples.

In contrast to current diagnostic tests for COVID-19, which detect genetic material from the virus in respiratory secretions, this test looks for antibodies to the virus in plasma, the liquid in blood, to provide information about a person’s immune response to an infection.

The test was launched April 6 at Stanford Health Care. It differs from an externally developed test that Stanford researchers used for a prevalence study during recent community screening events.

The Stanford-developed test takes two to three days for results. Stanford Health Care is able to test 500 samples per day, and the organization hopes to scale up quickly. The effort has been led by Scott Boyd, MD, PhD, associate professor of pathology and a leading expert in antibody research.

“It’s essential to have the right tools to understand the biology of the novel coronavirus,” said Lloyd Minor, MD, dean of the Stanford University School of Medicine. “This test takes us one step closer to answering the many public health questions about COVID-19.”

“Serological testing gives us a more comprehensive view of what’s happening in an individual who is infected, or has been infected, with the virus,” agreed Thomas Montine, MD, PhD professor and chair of pathology at the School of Medicine.

Commercial serological tests are now being developed around the world, but their quality is uncertain and variable, Montine said. “We thought this was an urgent medical need, and the usual supply chains were unreliable, so we decided to build our own.”

How it works

The Stanford test detects two different types of antibodies: IgM antibodies, which are made early in an immune response and whose levels usually quickly wane, and IgG antibodies, whose levels rise more slowly after infection but usually persist longer.