A widely used rapid COVID-19 test can produce false negatives if a certain solution is used to move or store patients’ samples, the test’s maker said.

Last week, Abbott Laboratories told health care providers not to use solutions known as “viral transport media” for samples tested on its ID NOW device, CNN reported.

Swabs with patient samples should be placed directly in the device, according to the company, which said that it immediately notified customers and the U.S. Food and Drug Administration when it identified the problem.

The device can provide positive results in as little as five minutes and negative results in 13 minutes. It has been distributed by the U.S. government nationwide, CNN reported.