What can be measured using immunoassays?

Immunoassays are laboratory tests that use antibody-antigen binding reactions to detect the presence of specific molecules. 

Immunoassays can be used to measure a wide range of biomolecules in clinical samples including proteins, antigens, antibodies, enzymes, and hormones. These measurements are required to track proteins, diagnose and assess disease, monitor therapeutic drugs, and evaluate environmental contamination as well as other applications in drug discovery and pharmaceutical industries.