What is phage display?
Phage display describes an in vitro selection technique in which a peptide or protein is genetically fused to a coat protein of a bacteriophage, resulting in display of the fused protein on the exterior of the phage virion, while the DNA encoding the fusion resides within the virion. This physical linkage between the displayed protein and the DNA encoding it allows screening of vast numbers of variants of the protein, each linked to its corresponding DNA sequence, by a simple in vitro selection procedure called “biopanning.” In its simplest form, biopanning is carried out by incubating the pool of phage-displayed variants with a target of interest that has been immobilized on a plate or bead, washing away unbound phage, and eluting specifically bound phage by disrupting the binding interactions between the phage and target. The eluted phage is then amplified in vivo and the process repeated, resulting in stepwise enrichment of the phage pool in favor of the tightest binding sequences.