The present invention relates to a complex in which an anti-cotinine antibody is bound to a conjugate of a binding material and cotinine, and a use of the complex. The complex according to the present invention may be used as an analysis tool in an in vitro biological assay method, and may retain the specific reactivity and the biological function of the binding material, and the capabilities of inducing complement-mediated cell cytotoxicity (CDC) and antibody-dependent cell cytotoxicity (ADCC) and a prolonged in vivo half-life, which are intrinsic characteristics of an antibody.