Objective       To optimize the protocols of long-PCR for amplifying full-length HCV genome based on plasmid pJFH-1.     Methods      Optimization of long-PCR strategies was performed by testing a series of primers

adding various concentrations of glycerol

DMSO or both

using different cycle systems to select the optimal long PCR conditions.     Results      Primers that have higher melting temperatures (65 ℃）could improve the efficiency of amplification. Glycerol of 5% and 10% or DMSO of 5% improved the specificity and efficiency of PCR amplification of full-length HCV genome. The promoting effect of glycerol was better than that of DMSO. Compared to three-stage temperature method

two-step temperature produced more PCR product.     Conclusion      Through the optimization of long-PCR protocol

full-length HCV genome is successfully achieved.