Abstract: An examination system that recognizes a glycosylated antigen in Dane particles of hepatitis B virus (HBV) and a neutralizing antibody that recognizes the glycosylated antigen and that exhibits an infection-inhibiting activity. It was elucidated that Dane particles are associated with specific glycan structures, and this enabled the construction of a new detection system for infectious, i.e., nucleic acid-containing, hepatitis B virus particles and the provision of a neutralizing antibody that recognizes a glycosylated antigen and that exhibits an infection-inhibiting activity.