The first COVID-19 diagnostic at-home self-test that provides rapid results has been approved by the U.S. FDA, the agency announced Tuesday. The Lucira COVID-19 All-In-One Test Kit is a molecular single-use test and is expected to cost $50 or less, the company said on its website. … The test, which works by swirling a self-collected swabbed sample in a vial which is then placed in a hand-held test unit, can provide results in 30 minutes or less, according to the agency. The unit's light-up display shows whether a person is positive or negative for the SARS-CoV-2 virus.