Comparison of two Taq-man Real-time PCR methods for detection of HBV cccDNA

Abstract

Objective To compare two Taq-man Real-time PCR methods for detection of hepatitis B virus covalently closed circular DNA (HBV cccDNA) in serum or liver tissue. Methods Two sets of primers and probes (common Taq-Man probe and MGB Taq-Man probe) were synthesized according to the reference papers, and the sensitivity and specificity of the two methods were compared using prepared plasmid as standard curve, and HBV DNA samples were exlracted from serum and liver tissue samples of hepatitis B patients. The samples were tested with both methods separately before or after the digestion with a Plasmid-Safe ATP-dependent Dnase (PSAD). Results Both of these two kinds of detection methods had a good linear relationship with the prepared plasmid as standard curve (R2 0.989 or 0.976 respectively, CV were within 4% ), and obtained good specificity when the HBV DNA samples were tested before or after digestion with PSAD. The common Taq-Man probe had lower Ct value than MGB probe when the samples in the same concentration. Conclusions Both methods can be used for HBV cccDNA detection. The common Taq-Man probe has slightly higher sensitivity than MGB probe, while the MGB probe has lower background than the common Taq-Man probe in our test. One can select the appropriate probe according to the need. Key words: Hepatitis B Virus; Covalently closed circular DNA; Real-time PCR