PCR is used as a preparative tool for the synthesis of a high-complexity double-stranded DNA library. In the example presented here, a mixture of synthetic oligonucleotides is used to synthesize a random peptide NNK library, where K is either T or G. The exclusion of A and C nucleotides at the third position decreases the occurrence of stop codons but still allows codons for all 20 amino acids.

Protocol: Use of PCR to Prepare a Double-Stranded DNA Library Encoding Random Peptides Protocol