... = Ct (target gene of sample) - Ct (refer-ence gene of sample)ΔCt (calibrator) = Ct (target gene of calibrator) - Ct(reference gene of calibrator)Ratio (folds of difference) of sample: calibrator ... J, Yang Y, Mu YX, Liu M, Lu L, Li Y, Zhu Y, Wu J:Inhibition of Hepatitis B virus gene expression by single and dual smallinterfering RNA treatment. Virus Res 2005, 112:100-107.21. Chen Y, ... posttranscriptional regulatory element. Virology 1998,248:46-52.35. Zang WQ, Li B, Huang PY, Lai MM, Yen TS: Role of polypyrimidine tractbinding protein in the function of the hepatitis B virusposttranscriptional...