HCV virus-like particles were constructed using a recombinant adenovirus containing encoding the HCV structural proteins (core, E1 and E2) of HCV 77H, genotype 1a. Briefly, the core/E1 genes were amplified from pBRTM_HCV 1-3011 plasmid containing the genome of HCV H77 genotype 1a (a gift from Prof C Rice). The core/E1 genes were amplified from pBRTM_HCV 1-3011 plasmid containing the genome of HCV H77 genotype 1a (a gift from Prof C Rice). The forward Core/E1 primer (59gCCTCTAgAgCCACCATgCATCACCATCACCAT-CACACAAgCACgAATCCTAAACTCAAAgAAAAACC 39) was designed to introduce an XbaI enzyme restriction site followed by a Kozak sequence, a start codon and a His(6) tag at amino terminal end of the core protein. The reverse primer of core/E1 (59 ggCTTAAgCCCggTgACgTgggTTTCC gCgTCgAC 39) was designed to amplify from the sequence downstream of the region corresponding to E1/E2 cleavage site (amino acids 383/384) and to introduce an Afl II restriction site at the 39 end. Next, the E2 genome was amplified using a forward primer (59CgACTAgT-gAAACCCACgTCACCgggggAAgTgCCggCCgC 39) that also introduced a SpeI site at the 59 end. The reverse E2 primer (59CgGATATCTCATCAC gCCTCCgCTTgggATATgAgTAA-CATCATCC 39) was designed to introduce a double stop codon and an EcoRV restriction site at the 39 end of the amplicon.