Antibodies from Phage Display Libraries as Immunochemical Reagents

The display of a repertoire of recombinant antibodies on the surface of filamentous phage by fusion to a minor coat protein has provided a powerful methodology for isolating the desired binding specificities (see Chapter 45 and ref. 1 ). Antibodies have typically been displayed on phage as single-chain Fv fragments (scFv [2 ]), in which the heavy chain variable region (VH) and the light chain variable region (VL) domains are linked together by a flexible polypeptide (3 ,4 ), or as Fab fragments (5 ) In general, antibodies have been displayed either at the N-terminus of the minor coat protein pill of filamentous phage (2 ), or at the C-terminal domain of pill (6 ). For Fab fragments, one chain is fused to pill, and the other assembles with the pill-fused chain after leader peptide-mediated secretion in the bacterial supernatant.