Multivalent and multispecific binding proteins, their manufacture and use.

(57) Although it consisted of the 1st domain that consists of a coupling field of a summary immunoglobulin heavy chain variable domain, and the 2nd domain that consists of a coupling field of an immunoglobulin light chain variable domain and the above-mentioned domain is chained, The polypeptide which cannot unite mutually and cannot form an antigen binding site unites, and forms the antigen unity multimer which is 多 value or can have multiplex singularity, for example, a dimer. A domain can be chained by the linker of short peptide, or can be joined together directly. The double singularity dimer can have a longer linker. Those displays on the surface of the bacteriophage for easy selection of the method of producing polypeptides, those multimers, and a repertory and the binder in question and much practicality are indicated.