The V5 epitope (N-Gly-Lys-Pro-Ile-Pro-Asn-Pro-Leu-Leu-Gly-Leu-Asp-Ser-Thr-C) is recognized by the anti-V5 monoclonal antibody (Invitrogen). Complementary oligonucleotides encoding the V5 epitope were designed in such a way as to generate SacII compatible termini following annealing (bold), and to preserve the reading frame when inserted into the SacII restriction site at nucleotide 123 within the 59 GS of the JV genome (underlined). The oligos were termed V5 Top (59-GGTAAGCCTATCCC-TAACCCTCTCCTCGGTCTCGATTCTACGAGC-39) and V5 Comp (59-TCGTAGAATCGAGACCGAGGAGAGGGT-TAGGGATAGGCTTACCGC-39). The oligos were phosphorylated and annealed as described previously and the duplex ligated to the SacII digested JV full length clone. Ligated DNA was used to transform E.coli Top10.