Fig 1. Production of HIV-1 epitope mutant virus libraries.

Double-stranded DNA encoding an HIV-1 genomic region including an epitope of interest was synthesized to represent every possible single and double amino acid variant within the epitope and its immediately flanking amino acids, using degenerate codons (NNK, where N is any nucleotide and K is guanine or thymidine, encoding every amino acid while reducing stop codons). This DNA was then substituted into the full length HIV-1 NL4-3 genome to create a plasmid HIV-1 library for virus production.