In recent decades, immunoassays have become widely used for the sensitive and specific investigation of a variety of different analytes, from proteins to steroids, drugs and microbes. In the five chapters of this book, immunoassay experts first establish the general principles of immunoassay before highlighting new developments, especially in the area of assay technology. The book illustrates the versatility of immunoassays and emphasizes how one type of assay is not suitable for all applications. The authors place the technology in context and explore pros and cons, recognizing that novel assays are still needed for many purposes (e.g., healthcare, forensics, environmental and food analysis).