Since Kohler and Milstein (9) developed a method to prepare the monoclonal antibody (McAb), the antibody has widely used in every field of biological science. As is well known, the McAb recognizes only one determinant of the antigen with high specificity and contains antibody class or subclass in the uniform pattern. Moreover, the hybridoma, once established, produces the homogeneous antibody molecule in the culture media continuously. On the other hand, McAb does not precipitate the antigen in the form of the immune complex of the large molecule, and shows cross-reactivity (11). In the application of McAb to immunohistochemical studies, it is necessary to