<p>A phage display library was affinity selected against indicated quantities of double-stranded DNA containing Rap1 binding sites under indicated salt conditions. Results from PCR of input phage library (input) or after second round of selection are shown. The intensity of a band is proportional to its abundance in the library. Lanes designated RAP1 indicate results of specific PCR against a single phage with the <i>RAP1</i> DNA-binding domain known to be in the library and the red arrows mark the expected size of this clone. Gel-isolation and sequencing of the selected bands at this location confirmed that they correspond to this clone. The blue arrows point out the PCR products corresponding to the <i>MCM1</i> DNA-binding domain (lower band) and <i>MCM1</i> ORF (upper band). The remaining bands show variable enrichment as a function of salt concentration and likely represent non-specific enrichment during the selection.</p
