Pyrosequencing of phage display libraries for the identification of cell-specific targeting ligands

High combinatorial phage display libraries have become an important tool in the search for ligand-receptor interactions. The advantage this approach offers is the ability to screen large repertoires of peptides, displayed on the coat proteins of bacteriophages, against a target at the same time. In addition, no prior knowledge is required of the target or the ligand. However, to characterize the peptides of interest a short length of the bacteriophage genome that encodes the peptide sequence requires DNA sequencing. The number of candidate bacteriophages can be large and so sequencing is expensive, time-consuming, and laborious. Therefore, a methodology using Pyrosequencing has been developed where 96-phage displaying a seven amino acid peptide can be analyzed simultaneously within 45 min and at a fraction of the cost associated with traditional automated Sanger sequencing.