Stanford Medicine surpasses a half-million COVID-19 tests

Stanford Medicine, one of the first medical centers in the country to conduct clinical tests for COVID-19, has remained at the cutting edge of coronavirus detection.

- By Bruce Goldman

Stanford Medicine's clinical virology lab began testing microbiological samples for COVID-19 last March.
Steve Fisch

Stanford Medicine has conducted more than 500,000 COVID-19 tests since the pandemic began. 

The medical center’s clinical virology laboratory began testing microbiological samples for COVID-19 on March 4, 2020, making it among the first labs in the country — and the first in California — to do so. 

Since that time, the lab’s throughput has increased considerably. Testing volume was as high as 4,000 samples daily at the peak of the most recent COVID-19 surge. With infection rates dropping, the lab is now conducting about 1,600 tests per day.

A year ago, the clinical virology laboratory had about 20 staff members. Since the COVID-19 pandemic reached the United States, the lab has transformed itself into a 24/7, three-shift juggernaut, with some 60 staff members, including technicians and scientists. 

Test samples have come to the lab not only from Stanford-affiliated health centers but from other medical facilities throughout the greater San Francisco Bay Area. 

Stanford Medicine was one of the first academic medical centers to partner with local public school districts to provide on-site support for COVID-19 testing of K-12 teachers and staff, enabling the safe re-opening of some schools this past fall. As of late January, the clinical virology laboratory had conducted over 10,000 COVID-19 tests for teachers.

Benjamin Pinsky, PhD, associate professor of pathology and of infectious diseases, began designing a clinical COVID-19 test after reading disturbing reports out of China early last year about the emergence of SARS-CoV-2, the virus that causes COVID-19. “Things really escalated from there,” he said. The United States soon experienced an explosion in COVID-19 cases. 

“As the pandemic has evolved, we’ve been able to stay at the cutting edge as far as testing goes,” said Pinsky, the medical director of the clinical virology laboratory. The lab, for example, was the first in the U.S. — and still the only — to offer a “minus strand” test that determines whether the virus is actively replicating in a patient’s body. The lab assesses patient specimens from across the country to distinguish people who may have persistent active infections from those with vestigial viral components in their blood. 

Christina Kong, MD, the medical director of Stanford Health Care’s pathology and clinical laboratories, said reaching the 500,000-test mark was a bittersweet achievement.

“For us, it’s a milestone in what’s turned out to be a long marathon in dealing with the pandemic,” said Kong, who also is a professor of pathology. “We’re finally seeing case numbers begin to decline, but our work is far from over. Our hope is that our testing innovations and efforts to identify infections and new variants in our community will continue to play a key role in controlling and ultimately ending the pandemic.”

About Stanford Medicine

Stanford Medicine is an integrated academic health system comprising the Stanford School of Medicine and adult and pediatric health care delivery systems. Together, they harness the full potential of biomedicine through collaborative research, education and clinical care for patients. For more information, please visit

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