Immunological assays are laboratory techniques used to detect and measure the presence of specific antibodies or antigens in a sample. These assays rely on the unique binding properties of antibodies to their corresponding antigens, allowing researchers to identify and quantify substances such as proteins, hormones, or pathogens in blood, serum, or other biological fluids. Common types of immunological assays include enzyme-linked immunosorbent assays (ELISA), Western blotting, and immunofluorescence. These methods are widely used in clinical diagnostics, vaccine development, and research to monitor immune responses and diagnose diseases, including infections and autoimmune disorders.