The present invention relates to methods of identifying an epitope on a protein that can be bound by an antibody. Methods of the invention typically involve a step of limited or restricted proteolysis of a protein using a single first protease or a combination of first proteases, and a further proteolysis step using a single second protease or combination of second proteases. The invention also relates to identified epitopes and to antibodies which bind to epitopes that have been identified by methods of the invention.