Target-assisted iterative screening of phage surface display cDNA libraries.

The novel screening format, target-assisted iterative screening (TAIS), comprises a simple and rapid two-step procedure for in vitro affinity selection of specific binders from enormous molecular diversities to the target molecule of interest. This detailed protocol describes the application of TAIS to a T7 phage-displayed complementary DNA (cDNA) library with a protein domain as a target. Protocols for purification of the target as glutathione-S-transferase (GST) fusion protein and modifications of the purified target that are required for the screening complement the TAIS protocol. The described application is a method of choice for the researchers interested in the identification and characterization of novel protein-protein interactions mediated by peptide recognition domains.