Figure 1. HBsAg-specific monoclonal antibodies cloned from HBsAg-specific memory B cells. (A) Flow cytometry plots of PBMCs of healthy volunteers received recombinant hepatitis B vaccine with anti-CD19, anti-IgG and biotin-HBsAg. (B) Purified mAbs run on a 10% SDS-PAGE under reducing conditions. (C) HBsAg-binding ELISA for mAbs from CD19⁺IgG⁺HBsAg⁺ cells.