The future of coronavirus testing is in Greenville, N.C. Ariana Eunjung Cha Diane Bell reads the instructions to an at-home coronavirus test kit in Greenville, N.C. (Melissa Sue Gerrits for The Washington Post) After a busy day of grocery shopping and other errands, Diane Bell slid into a kitchen chair and took out her at-home coronavirus test kits. She swabbed both her nostrils and mixed a few chemicals, and within a few minutes, a blue line materialized on an indicator strip. “Negative!” she called out to her partner. It was her seventh test in three weeks, and so far, so good.