Monoclonal Fab Fragments from Combinatorial Libraries Displayed on the Surface of Phage

Abstract

The combinatorial antibody approach captures the immune repertoire within a library of bacteria or their viruses (phage). Current molecular biology techniques allow the construction of repertoires of a size that at least matches if not surpasses the size of the primary animal repertoire, about 10⁸. Escherichia coli are competent producers of antibody Fab and scFv fragments. To survey repertoires of this size for antibody fragments of the proper specificity and highest affinity, a phage display system that allows an affinity-based selection of clones was developed. These developments have at least three important consequences: (i) they allow direct cloning and expression of human Fab fragments; (ii) they allow the creation of synthetic antibodies; and (iii) they allow the in vitro evolution of antibody specificity and affinity. For the crystallographer, these developments will provide unique opportunities for the study of molecular recognition .c 1993