Tulane Researchers Develop COVID- 19 Blood Test
NEW ORLEANS – Tulane University researchers say they have developed a highly sensitive blood test that can detect COVID-19 in rare cases when infections were missed by nasal swab PCR tests. The research results were published in The Journal of Clinical Investigation.
Most PCR-based COVID-19 tests use nasal swabs because the virus actively replicates in the upper respiratory tract immediately after infection. However, virus levels in the nose wane through the course of infection. Studies have shown that the virus can be detected in blood and blood viral levels can indicate disease severity, but PCR tests aren’t sensitive enough for reliable blood screening.
Tony Hu, Weatherhead Presidential Chair in Biotechnology Innovation at Tulane University School of Medicine, developed a test that uses CRISPR gene-editing technology. His test amplifies a genetic fragment of the SARS-CoV-2 virus, similar to conventional testing assays, but then uses CRISPR to greatly amplify the signal produced in response to this target DNA region.
The test could be especially useful in clinical applications where patients may be presenting with severe symptoms of COVID-19 but consistently test negative for the disease using nasal swab PCR tests, said Hu.
“This approach could not only improve the accuracy of COVID-19 diagnoses but it may also help doctors predict the severity of infection and whether patients have fully cleared the virus,” he said.