This chapter explains how antibody-based, qualitative tests were developed starting in the nineteenth century. The principle of immunoprecipitation and the methods that use it are explained, including passive gel diffusion-based techniques. This leads to a section on immunoelectrophoresis. Later methods derived quantitative capability from these techniques, such as single radial immunodiffusion and rocket electrophoresis. Quantitative in-liquid methods are also described, including turbidimetric and nephelometric techniques. The Technicon autoimmunoprecipitin method is reviewed in detail. The author explains how particle-enhanced immunochemistry developed, including particle counting immunoassay. There is also a section on key advances in antibody-labeling techniques.

Dr. Robert F. Ritchie founded the Foundation for Blood Research in the early 1970s. The Foundation is dedicated to identifying, managing and preventing human disease through clinical and laboratory investigation. Under Dr. Ritchie’s leadership, FBR has amassed one of the world’s largest clinical databases of serum protein results. Dr. Ritchie developed a laboratory method for measuring serum proteins that allowed the major serum proteins to be measured more rapidly and reliably than with conventional methods. Dr. Ritchie also founded Atlantic Antibodies, a subsidiary of FBR that became an international manufacturer of laboratory reagents. Most recently, he has spearheaded the Maine Arthritis Partnership, a unique project aimed at improving care for Maine’s aging population. Dr. Ritchie has held numerous roles with the World Health Organization, the Food and Drug Administration and the International Federation of Clinical Chemists.

Immunochemistry, immunization, immunoprecipitation, antibody, ring test, precipitin, avidity, immunoelectrophoresis, immunofixation, staining, radial immunodiffusion, rocket electrophoresis, turbidimetry, nephelometry, latex beads, particle-enhanced immunoassay, label.