HBcAg subtype adw2 produced in E.Coli, is a single, non-glycosylated, polypeptide chain containing 1-149 amino acids and having a molecular weight of approximately 20kDa. HBcAg adw2 1-149 protamine-like domain was truncated in order to enhance the differentiation of anti-HBe in ELISA test. HBcAg was purified by proprietary chromatographic techniques.