Fig. 1.

Strategy to assemble a DENV infectious cDNA clone as a BAC: A four-step cloning strategy, in which the overlapping cDNA fragments, termed overlapping PCR 1, PCR 2, PCR 3 and PCR 4, were sequentially cloned into the plasmid pBeloBAC11 and used to generate the infectious clone pBAC-DENV-FL. This plasmid includes the CMV promoter precisely joined to the DENV genome, followed by the hepatitis delta virus ribozyme (RZ) and the bovine growth hormone termination and polyadenylation sequences (BGH). The genomic positions of the relevant restriction sites used for the assembly of the full-length cDNA clone are illustrated at the top.