Objective To establish a peptide nucleic acid clamping PCR assay for detecting hepatitis B virus(HBV) drug resistance mutation.Methods RtM204I(ATT) mutant,rtM204V(GTG) mutant and rtM204(ATG) wild-type plasmids mixed at different ratios were detected for mutations by PNA clamping PCR assay and direct sequencing,and the sensitivity and specificity of the two methods were compared.Serum samples from 85 patients with chronic HBV infection were detected for drug resistance using the two methods.Results The sensi...