METHOD FOR MEASUREMENT OF CONCENTRATION OF ANTIGEN

摘要

Disclosed is a detection method which can detect an antigen in a simpler, more efficient and more stable manner and with higher sensitivity even when the antigen has a low molecular weight. The detection of an antigen is carried out by using a fusion protein. The fusion protein comprises the following polypeptides and proteins in this order or in inverse order to this order: a polypeptide containing a VH region of an antibody; a specific protein; a linker peptide; a partner protein which is capable of binding to the protein and whose binding to the protein can be detected; and a polypeptide containing a VL region of the antibody. The fusion protein is so constructed that the binding between the antigen and the polypeptide containing the VH region and the polypeptide containing the VL region induces the binding between the protein and the partner protein.