Development of Magnetic Capture Hybridization and Quantitative Polymerase Chain Reaction for Hepatitis B Virus Covalently Closed Circular DNA

Background: hepatitis b virus (hbv) covalently closed circular dna (cccdna) served as a vital role in the life cycle of the virus and persistent infection. however, specific and quantitative methods for cccdna detection have not been available. objectives: our aim was to develop and primarily evaluate a quantitative method for hbv cccdna based on magnetic capture hybridization and quantitative pcr technology. materials and methods: the functionalized-nanoparticles specifically to capture hbv cccdna, located on both sides of relaxed circle dna (rcdna) gap, were designed. then, magnetic capture hybridization and quantitative pcr (mch-qpcr) assay were developed and its performance was primarily evaluated with cccdna standards and serum samples of patients with chronic hepatitis b. results: specific nanoparticles of cccdna capture were prepared and a ma gnetic capture hybridization and quantitative assay method for cccdna was developed successfully. the limit of detection was 90 iu/ml, and a good linear relationship in the range of 10^2 - 10^6 iu/ml was revealed (r2 = 0.994) with the mch-qpcr. compared with directly real-time pcr, a high content of hbv dna did not affect the detection of cccdna for the mch-qpcr method, and there was no cross-reactivity between cccdna and rcdna. conclusions: the novel mch-qpcr method has good sensitivity and specificity. it could meet the requirement of clinical routine detection.