Practice question

Phage display is a combinatorial technique for studying protein interactions and affinity selection. Foreign DNA sequences are cloned into genes encoding filamentous phage coat proteins, leading to surface presentation of peptide or protein fusions. The displayed protein retains ability to bind ligands, antibodies, or receptors immobilized on solid support. After washing, bound phages are eluted and amplified in E. coli, enabling iterative enrichment. Unlike SPR, Co-IP, and FRET which measure biophysical binding, phage display directly couples genotype to phenotype for directed evolution.