Handbook of Immunoassay Technologies: Approaches, Performances, and Applications unravels the role of immunoassays in the biochemical sciences. During the last four decades, a wide range of immunoassays has been developed, ranging from the conventional enzyme-linked immunosorbent assays, to the smartphone-based point-of-care formats. The advances in rapid biochemical procedures, novel biosensing schemes, fully integrated lab-on-a-chip platforms, prolonged biomolecular storage strategies, device miniaturization and interfacing, and emerging smart system technologies equipped with personalized mobile healthcare tools are paving the way to next-generation immunoassays, and are all discussed in this comprehensive text. Immunoassays play a prominent role in clinical diagnostics as they are the eyes of healthcare professionals, helping them make informed clinical decisions via confirmed disease diagnosis, and thus enabling favorable health outcomes. The faster and reliable diagnosis of infections will further control their spread to uninfected persons. Similarly, immunoassays play a prominent role in veterinary diagnostics, food analysis, environmental monitoring, defense and security, and other bioanalytical settings. Therefore, they enable the detection of a plethora of analytes, which includes disease biomarkers, pathogens, drug impurities, environmental contaminants, allergens, food adulterants, drugs of abuse and various biomolecules.