[A simplified method for detection of genomic subtyps of HBV S-gene].

When the 513 bp amplified fragments of HBV S-gene, known subtypes, were digested with Msp I and BamH I, the following phenomena appeared: adr subtypic 513 bp was fragmentized to 320 bp and 193 bp by Msp I; ayw subtype was digested and fragmentized to 295 bp and 218 bp by BamH I; ayw could also be fragmentized to become 326 bp and 187 bp digested by Msp I. Howerev, adw subtype was not digested by Msp I and BamH I nor adr by BamH I. The experimental patterns in agarose gel electrophoresis were tallied with the expected patterns. Each HBV subtypes gave unique size of digestive fragments which was easy to observe and distinguish on agarose gel. This study provided a new classification scheme for HBV-DNA and could be used for epidemiological investigation of HBV infection.