Characterization of antibodies

· Early physical – chemical studies were done with Ig G from horse, rabbit and human

· Important structural features were predicted even before sophisti-cated studies were available

· Molecular weight was calculated from sedimentation and diffusion studies

· Asymmetrical and or non globular form by viscosity studies

· Globular domain structure from unique susceptibility to proteolytic enzymes

· Two antigen binding sites by hapten antibody reactions

· Thus early studies predicted three functional domains and have been confirmed