CDC Director Robert Redfield told POLITICO on Tuesday that he is not confident that U.S. labs have an adequate stock of the supplies used to extract genetic material from any virus in a patient’s sample — a critical step in coronavirus testing.

“The availability of those reagents is obviously being looked at,” he said, referring to the chemicals used for preparing samples. “I’m confident of the actual test that we have, but as people begin to operationalize the test, they realize there’s other things they need to do the test.”

The coronavirus task force convened by the White House is also aware of the shortages, and one official said members are working on it.