The present invention relates to methods of screening for commonly shared light chains, in which the method comprises the steps of (a) generating a host secreting the heavy chain of an antibody that binds to a desired antigen (b) introducing an antibody light chain library into the host of step (a) to generate libraries presenting antibodies composed of the heavy chain and the light chains (c) selecting a library presenting antibodies that bind specifically to the desired antigen of step (a) (d) introducing the library selected in step (c) into a host secreting the heavy chain of an antibody that binds to a desired antigen different from the antigen of step (a) to generate libraries that display antibodies composed of the heavy chains and light chains and (e) selecting a library that displays antibodies that bind specifically to the desired antigen of step (d).
