Fig. 1.

Mutation pattern of the hepatitis B surface antigen (HBsAg) of 25 blood donor samples with HBV DNA. M54923 (Genotype B, adw) and AP011097C (C, adr) obtained from GenBank are used as reference sequences. Dots represent amino acids identical to those in the M54923. Amino acids that determine HBsAg serotype are shaded. Three substitution patterns were observed: T123A (in 1 donor), M133L (in 1 donor), and T143M (in 5 donors). wt represents sequences with no amino acid substitution in 18 donors