Construction of a semisynthetic antibody library using trinucleotide oligos.

A semisynthetic antibody library composed of single chain Fv fragments (scFv) was constructed by replacing the heavy chain CDR3 region of a human scFv by a random sequence of eight amino acids using trinucleotide codons. After cloning into a phage display vector, an antibody library was generated with a complexity of 8 x 10(8) independent clones. The library was screened for binders to dinitrophenol, fluorescein isothiocyanate and 3-nitro-4-hydroxy-5-iodophenylacetic acid. scFv antibodies that specifically bound the antigen were obtained in each case.