Immunoaffinity purification of antibodies is used to purify antigen-specific antibodies from a preparation of polyclonal antibodies. Such purification is commonly needed in the production of antipeptide antibodies, where it is used to concentrate the desired antibodies and separate them from those raised against carrier proteins. It is also used for the more general purpose of removing unwanted, nonspecific binding activity from polyclonal antibody preparations. - [Read Purification of Antibodies on an Antigen Column Protocol]