Researchers at Michigan State University in East Lansing have adapted and validated a COVID-19 testing method that they say is 500 times more sensitive than the standard test. The U.S. Food and Drug Administration has been asked to grant emergency use authorization for the test, which could be ready by the end of the month.
The test’s higher sensitivity reduces the number of false negative test results, which incorrectly diagnose people as free of the disease, allowing them to continue life as usual and infect others. The standard test returns an estimated 20 percent to 30 percent false negative results in patients who have not yet exhibited symptoms due to a low amount of the virus in a test sample.
Bio-Rad Laboratories in California, which developed and manufactured a machine called the Droplet Digital PCR that MSU’s researchers used in validating the new method, is asking the FDA to grant emergency use authorization for the test. The application process is expected to be completed this month, allowing labs across the country to begin offering the test immediately.
The new test is based on information that was posted on medRxiv.org by researchers in China. The MSU team adapted the test shown in the study.
Using the Droplet Digital PCR, the researchers tested genetic material in the laboratory before using human test samples from volunteers. The machine amplifies the genetic material in a small sample and then calculates how much of the virus is in a patient’s body.
After receiving expedited approval from MSU’s institutional review board, researchers tested university faculty and staff who volunteered, including one who previously had tested positive for COVID-19.
“We could see the subject’s viral load was off the chart,” says Jack Lipton, chair of the College of Human Medicine’s Department of Translational Neuroscience, who led the team. He added that the staff member is recovering. A subsequent retest using the new method showed that the staff member’s viral load had dropped significantly.
The researchers used different chemical reagents than those that have been in short supply for the standard test, Lipton says. The lack of supply is slowing down manufacturing of the standard test.
While MSU’s Department of Translational Neuroscience is not a clinical health provider and therefore is not authorized to offer the test to patients, the Droplet Digital PCR machines are in laboratories all over the country.
The researchers have made their findings available to other researchers, and other teams are using the method to reexamine previous samples that came back negative under the standard test.
“The more testing anyone can do in this crisis when lives are on the line, the better,” Lipton says. “If we can use our skill sets to help other people, this is what we can do. It’s just the right thing to do.”
The study the researchers based their work on is available here.