Immunochemistry is a branch of science that combines immunology and chemistry to study the interactions between antibodies and antigens. Antibodies are proteins produced by the immune system to identify and neutralize foreign substances, while antigens are molecules that trigger an immune response. This field is essential for understanding how the immune system works and for developing diagnostic tests and treatments. In immunochemistry, various techniques are used to detect and quantify these interactions, such as enzyme-linked immunosorbent assay (ELISA) and Western blotting. These methods are widely applied in research, clinical diagnostics, and vaccine development, helping to advance our knowledge of diseases and improve healthcare outcomes.