Rapid screening of phage displayed protein binding afinities by phage ELISA

Abstract Monovalent phage display enables a single protein (or peptide) molecule to be presented on the surface of a phage particle. This protein is translated from a phagemid vector as a fusion linked to the natural pIII coat protein in an Escherichia coli cell coinfected with helper phage. The display achieves monova- lency since the fusion protein rarely substitutes for the native pIII protein from the helper phage genome. While display can be highly variable, typically just 0.05-5% of these phages actually display the protein of interest (1).