Abstract: The present invention relates to a method for in vivo molecular evolution of antibody function. According to the present invention, a nucleic acid encoding a CDR that is normally contained in a framework (the “original framework”), which differs from a selected master framework, is amplified from an immunoglobulin gene and is inserted into a nucleic acid encoding the selected master framework. The invention further provides an antibody library, such as a phage display library, and methods of making the same.

Abstract: A method for selecting nucleic acid sequences encoding ligand and receptor molecules capable of specific binding to each other is disclosed in which nucleic acid encoding ligand or receptor molecules is expressed in a host microorganism in combination with a surface molecule, such as E. coli pili, so that the ligand or receptor are displayed on the surface of the host microorganism. A replicable genetic unit, such as a filamentous bacteriophage, is used to display candidate binding partners to the ligand or receptor, with the binding of the ligand or receptor to the candidate binding partner mediating the transfer of nucleic acid from the replicable genetic unit to the microorganism. The method can be highly selective as the host microorganism is modified so that it does not display the surface molecule other than as a fusion with the ligand receptor molecule. The method is rapid and simple and opens up new applications based on the detection of ligand and receptors where both are unknown.

Abstract: The present invention provides a method for producing a polynucleotide sequence encoding an antibody variable domain, the variable domain comprising complementarity-determining regions (CDRs) located within a selected framework (the ‘master framework’), the method comprising the steps of (a) providing at least one nucleic acid molecule encoding one or more CDRs and associated framework regions (the ‘original framework’), (b) amplifying at least one CDR-encoding portion of the nucleic acid molecule(s) of step (a) using one or more pairs of oligonucleotides as amplification primers and (c) assembling a polynucleotide sequence encoding an antibody variable domain by combining the amplified CDR-encoding nucleotide sequences produced in step (b) with nucleotide sequences encoding said master framework, wherein the oligonucleotide primers of step (b) comprise nucleotide sequences which differ from the corresponding nucleotide sequences encoding said master framework.