Scientists at The Scripps Research Institute discovered antibodies that can prevent infection from strains of hepatitis C virus (HCV) by attaching to sites on the viral envelope that seldom mutate. One of the new antibodies, AR4A, shows broader HCV neutralizing activity than any previously reported anti-HCV antibody. Erick Giang, a research assistant, conducted a panning technique on envelope glycoproteins E1-E2 complex and a panel of antibodies derived from the blood of a chronic HCV infected person. Giang catalogued 73 new anti-HCV antibodies, which bind to five distinct ‘antigenic region’ on the E1-E2 complex. AR4A bound to an almost-unvarying spot on E1-E2 complex, close to the surface of the virus’s outer coat of fat molecules. The new HCV antibodies, AR4A and AR3A, can possibly be useful in preventing new HCV liver infections in liver transplant patients, similar to antibody-based treatment which has worked well for liver transplants to patients with hepatitis B virus.