According to a July 17 study published in the International Journal of Geriatrics and Rehabilitation, 50 percent of nucleic acid coronavirus tests distributed by the Centers for Disease Control and Prevention (CDC) provided inaccurate results. The study's lead author, Sin Hang Lee, MD, director of Milford Molecular Diagnostics Laboratory, found that the testing kits gave a 30 percent false-positive rate and a 20 percent false-negative rate. To determine these false-positive and false-negative rates, the Connecticut State Department of Public Health Microbiology Laboratory provided Lee 20 tests, which were then re-tested using his own methodology, which examines samples on a cellular level, rather than just testing fluid with no cellular matter from potentially infected oral and nasal secretions. While the results of Lee's testing may be alarming, they also pointed to yet another discovery: new mutations of the virus. Two tests that initially provided false-negatives and one test that yielded a positive result were actually found to be positive for coronavirus and a mutation of the virus, meaning two variants of the virus can simultaneously infect one person. However, it's not just the test you use that may be contributing to inaccurate results-when you get tested is important, too. Getting tested the day a person is infected with coronavirus will likely yield a 100 percent false-negative rate; by day 8 after becoming infected, however, that rate drops to just 20 percent.