Short chain variable fragments (scfv) are generated by randomly combining the light and the heavy chains of an immunized mouse antibody repertoire. This recombination event, that does not occur in nature, creates a huge diversity of molecules. The size and diversity are checked and are found to contain 10⁸ unique molecules. 

After selection of the desired antibodies by phage display, these molecules are reformatted into full length chimeric antibodies for therapeutic applications.

A number of such libraries are being developed against cancer and autoimmune disease tissues with the objective of identifying  therapeutic antibodies against established or novel targets.