If you're looking to get tested for COVID-19, the draw of taking an at-home test is obvious. You can save time and avoid coming into contact with someone who might be infected. Pretty ideal. Even better, at-home COVID-19 tests are likely to be highly accurate, says Alexander J. McAdam, M.D., Ph.D., medical director of the Infectious Diseases Diagnostic Division at Boston Children's Hospital and associate professor of pathology at Harvard Medical School. Most at-home tests that people have been talking about are RT-PCR or molecular tests, which "work by using chemical reactions that make many, many copies of the viral genome, and detecting those copies," explains Dr. McAdam. Once a lab technician receives a specimen (usually, mucus from the throat or nose), they use a chemical to extract genetic material from any virus on the swab, according to the Food and Drug Administration (FDA). They then use a machine to detect whether COVID-19 is present; the machine indicates a "positive" or "negative" result, accordingly. (Related: Everything You Need to Know About Coronavirus Testing)