Immunoassays are laboratory techniques used to detect and quantify specific proteins or other substances in a sample, such as blood or urine. They rely on the principle of antigen-antibody interactions, where antibodies bind to their target antigens, allowing for the measurement of the substance of interest. Common types of immunoassays include ELISA (enzyme-linked immunosorbent assay) and Western blotting. These tests are widely used in clinical diagnostics, research, and drug development. They can help identify diseases, monitor health conditions, and evaluate the effectiveness of treatments. Immunoassays are valued for their sensitivity and specificity, making them essential tools in the field of immunology.