Detection of hepatitis B virus genotypes A to D by the fluorescence polarization assay based on asymmetric PCR

The hepatitis B virus genotypes A and D have global distributions, while the hepatitis B genotypes B and C are predominant in Asia. Individuals infected with genotype C or D have a lower response rate to therapy than individuals infected with genotype A or B. The conventional detections of hepatitis B genotypes A to D, however, have not been used routinely due to technical difficulties and high costs. A simple and cost-effective method for simultaneous detection of the hepatitis B genotypes A to D has been developed. A pair of general primers in the preS region of the hepatitis B were used in an asymmetric PCR. Four probes specific for the hepatitis B genotypes A to D labeled with different fluorophores hybridized, respectively with their target amplicons, and the hybridization increased the fluorescence polarization (FP) values. The genotypes were determined by the increased fluorescence polarization values. DNA extracted from 1398 samples was detected by the FP and the type-specific PCR assay in parallel. No significance difference was found between the two methods.