Abstract
Background and Objectives
Hepatitis B virus (HBV) infection remains a serious global health challenge. Hepatitis B infection is one of the major diseases transmitted by blood transfusion. Infection with the virus can cause extensive liver damage.  So far, 10 genotypes have been identified for hepatitis B. The aim of this study was to do Hepatitis B virus genotyping in asymptomatic HBV blood donors in Tehran.
 
Materials and Methods
In this cross-sectional study, 20 HBsAg positive blood donors tested by ELISA were examined. After viral DNA extraction, the pres gene was amplified by Nested-PCR method and the virus genotype was aligned with the references sequence by Clustal w software.
 
Results
Samples were sequenced after Nested-PCR was done. Hepatitis B virus genotype was determined in all 20 blood donors with hepatitis B to be genotype D.
 
Conclusions 
Prevalence of genotype D in study subjects was 100%.  This result can be used in preparation of hepatitis B diagnostic kits. Identifying genotypes can also help physicians identify patients at higher risk for disease progression and adopt better treatment strategies.