A Nanoscale Mutation-Sensitive On/Off Switch Based Assays for the Detection of Hepatitis B Virus Lamivudine-Resistant...

Long-term usage of lamivudine in the treatment of chronic hepatitis B virus (HBV) infection induces the emergence of drug resistance. Sensitive and specific methods aimed at detecting the mutants are clinically useful and required. The purpose of this study was to develop methods for detecting the mutations of YMDD, rtL180M, and rtV173L by nanoscale mutation-sensitive switch consisting of high fidelity polymerase and phosphorothioate-modified allele specific primers. Four assays for these hotspot mutations have been developed with the sensitivity of 100 copies and specificity of at least three log scales for matched templates over mismatched templates. In the condition of multiplex PCR, the sensitivities of these assays are approximately 1000 copies and specificities with two log scales in discrimination of mutant alleles over wild type sequences. These newly developed assays are rapid, accurate, and cost-efficient in detection of lamivudine-related HBV mutants.