1 Introduction.- 2 Importance of the immune system to life.- 3 Immunology and immunochemistry.- 4 Antigens.- 5 The major histocompatibility complex.- 6 The immunoglobulins (antibodies).- 7 Biosynthesis of antibodies.- 8 Preparation of pure immunoglobulins.- 9 Endogeneous immunomodulators (immunohormones).- 10 The complement system.- 11 Antigen-antibody reactions in vitro.- 12 Immunochemical methods.- 13 Phagocytosis.- Abbreviations.- Glossary of terms commonly used in immunochemistry.- Author index.