WW Selection II, Round 3 Library XP
Phage library DNA was isolated by phenol/chloroform extraction and ethanol precipitation. 50 ng of phage DNA was amplified using the Phusion HF system and the previously-described DF-97_PCR_Long primers (Fowler et al. 2010, Supplementary Table 3) for 15 cycles according to the manufacturers instructions (New England Biolabs, Ipswitch, MA). The product was isolated using the Qiaquick PCR purification kit (Qiagen, Germantown, MD) and purified using the Ampure reagent (Beckman-Coulter, Danvers, MA). Concentrations were determined using the Quant-IT dsDNA HS kit according to the manufacturers instructions (Invitrogen, Carlsbad, CA). Total DNA from each library was loaded into separate lanes and sequenced using a Genome Analyzer IIx (Illumina, San Diego, CA). The forward primer sequence was gctcggggatccgaattctgagatcccagac, and the reverse primer sequence was cggagcggtaacgttcatctgagacagcatagcttt.