Immunodiagnostics is a diagnostic methodology that uses an antigen-antibody reaction as their primary means of detection. The concept of using immunology as a diagnostic tool was introduced in 1960 as a test for serum insulin. Immunodiagnostic tests use antibodies as reagents whose results are used to aid diagnosis and are widely used in many scientific disciplines. Perhaps the most widespread and obvious use is in clinical applications, but immunodiagnostic tests are also used in other fields such as forensic science and environmental and food analysis. The different types of test range from simple manual methods to fully automated systems with sophisticated integrated detection.