Quantification of HDV total RNA (genome equivalent) copies and HBV genome equivalent copies HDV Viral RNA was isolated with Trizol reagent following manufacturer's instructions. Total RNA was reverse transcribed into cDNA with random primers (PrimeScript RT kit; Takara) and 2 μl of the cDNA was used for real-time PCR assay. Primers for quantifying HDV total RNA or genome equivalent copies are complemented with the delta antigen coding region of HDV RNA genome: forward primer HDV-1184F, 5′-TCTTCCTCGGTCAACCTCTT-3′, and backward primer HDV-1307R, 5′-ACAAGGAGAGGCAGGATCAC-3′.