Methods for producing members of specific binding pairs

A method for producing a binding molecule specific for a particular target epitope or antigen, which method comprises the steps of:

• producing a population of filamentous bacteriophage particles displaying at their surface a population of binding molecules, wherein each binding molecule in the population of binding molecules has a binding domain and the population of binding molecules has a range of binding specificities, wherein the binding domain of the binding molecules consists of an antibody heavy chain variable domain with the structure of FR1-CDR1-FR2-CDR2-FR3-CDR3-FR4, and wherein each filamentous bacteriophage particle contains nucleic acid with a nucleotide sequence encoding the binding molecule expressed from the nucleic acid and displayed by the particle at its surface;
• selecting for a filamentous bacteriophage particle displaying a binding molecule with a desired specificity by contacting the population of filamentous bacteriophage particles with a target epitope or antigen so that individual binding molecules displayed on filamentous bacteriophage particles with the desired specificity bind to said target epitope or antigen.