A 60 Minutes investigation revealed that federal officials knew many of the antibody tests suddenly flooding the market were seriously flawed, but continued to allow them to be sold anyway. In early March, Dr. Alex Marson of UC San Francisco, and Dr. Patrick Hsu, an assistant professor of bioengineering at UC Berkeley, assembled a team of 50 scientists to do what the FDA had not: test the antibody tests. All but one test delivered so-called false-positives, meaning they mistakenly signaled antibodies in people who did not have them.