How do you make site-directed or permutation scanning library? August 14, 2019 12:00 We synthesize the gene and then amplify with degenerate PCR primers. Related articles How do you make randomized and degenerate libraries? What QC is done after plasmid prep? How to calculate the diversity of a site-directed or permutation scanning library? How to convert three letter peptide sequence to one letter peptide sequence, or vice versa? Why should oligonucleotides be purified?