Immunoassay techniques have become essential in various fields of pure and applied research. This volume of the well known Laboratory Techniques series will be of assistance to those who have plans or are making efforts to develop ultrasensitive enzyme immunoassays for antigens and antibodies. The volume describes factors limiting the sensitivity of noncompetitive solid phase enzyme immunoassays, methods to overcome difficulties limiting sensitivities, methods to perform ultrasensitive enzyme immunoassays as rapidly as possible, and protocols of enzyme labeling and enzyme assays as well as ultrasensitive enzyme immunoassays. Ultrasensitive and Rapid Enzyme Immunoassay, with its clear presentation and up-to-date information, will be essential to scientists in pharmaceutical companies and in applied research.