A new test can rapidly screen thousands of nasopharyngeal swab samples for the concerning, more contagious SARS-CoV-2 variants first identified in the UK, South Africa and Brazil, researchers said. The test uses probes that change color at different temperatures depending on whether it detects a specific mutation, called N501Y, that is present in all three variants. The test, for now, is not capable of differentiating between them, so positive samples would need further testing to identify the particular variant, said David Alland of Rutgers University in New Jersey, coauthor of a report posted on medRxiv ahead of peer review. "Our next job, already mostly completed, will be to add to the test so that a second mutation ... called E484K, can also be detected," he said. "This will distinguish variants ... from the UK from those of South African or Brazilian origin." The test should continue to detect these variants of concern even if the virus continues to mutate, he said. In those cases, the temperature at which the probes change color will be altered, and any unforeseen color change will flag a sample as likely containing a new mutant, Alland said. The assay is open-source, so it can be updated by the Rutgers researchers or other teams. —Reuters Staff Source