Selection and characterisation of recombinant single-chain antibodies to the hapten Aflatoxin-B1 from naive recombinant antibody libraries

Selection of antibodies from large repertoire phage display libraries has b ecome a common technique for isolation of specific antibodies to antigens. Many of these libraries are shown to contain antibodies specific to haptens , but only when these haptens are derivatised or conjugated to an immobilis ing molecule, such as bovine serum albumin (BSA). There has been little dem onstration of the suitability of naive recombinant antibody libraries for i solating antibodies that bind low molecular weight haptens in the absence o f a carrier molecule and few have addressed the problems associated with se lecting antibodies that only recognize the combination of hapten and the ca rrier molecule. We have panned two-phage antibody libraries against Aflatox inB1-BSA and screened single-chain antibody fragments for binding to Aflato xinB1-BSA and Aflatoxin-B1. Many of the antibodies isolated specifically bo und AflatoxinB1-BSA, but not soluble Aflatoxin-B1 or BSA. Modification of t he protocol led to isolation of single-chain fragment variable antibody dom ain (scFv) antibodies that specifically bound soluble Aflatoxin-B1 with an affinity of 6 x 10(-9) M. (C) 2001 Elsevier Science B.V. All rights reserve d.