For months, the call for coronavirus testing has been led by one resounding refrain: To keep outbreaks under control, doctors and researchers need to deploy the most accurate tests available — ones reliable enough to root out as many infections as possible, even in the absence of symptoms.

That’s long been the dogma of infectious disease diagnostics, experts say, since it helps ensure that cases won’t be missed. During this pandemic, that has meant relying heavily on PCR testing, an extremely accurate but time- and labor-intensive method that requires samples to be processed at laboratories.