In general, polyclonal antibodies are less sensitive to conformational and minor structural changes within the antigen protein than are monoclonal antibodies. Due primarily to the very high affinities and the multiple recognition sites with which polyclonal antibodies can bind the antigen proteins, even complexed forms (such as enzyme-inhibitor complexes) and fragments (such as proteolytic cleavage products or recombinant products) are still recognized by polyclonal antibodies.