This textbook provides an accessible and comprehensive introduction to the basic principles of immunological methods. It offers a fundamental insight into the performance of different immunoassays and their areas of application. Each chapter in Immunoassays begins with a basic introduction to the topic before going on to cover important details for everyday laboratory work and professional practice. Readers will gain confidence in using the methods as potential problems are discussed in detail and troubleshooting sections help to solve them. The book covers all the classic and essential techniques, such as enzyme-linked immunosorbent assay (ELISA), dot blot, and western blot, as well as the latest advances in polymerase chain reaction (PCR), flow cytometry, fluorescence microscopy, and 3D cell and organoid culture. Importantly, the book also covers regulatory requirements and provides information on quality systems with various mandatory guidelines and regulations, such as in-vitro diagnostics, medical devices, the pharmaceutical industry, and food analysis. Packed with many practical tips, this textbook is an invaluable resource for beginners and experienced practitioners alike. It is aimed at researchers and students in the life sciences and biomedicine, as well as laboratory assistants.