Binding Site specializes in the research, development and production of immunodiagnostic kits and reagents for use in the investigation of human and veterinary diseases. The first commercial kit for the measurement of human IgG subclass levels were developed at the Binding Site laboratories in 1984 and used by researchers around the world to gain a better understanding of the role of IgG subclasses in health and disease. In 1988, the kits were recommended for in-vitro diagnostic use' in the United States and Binding Site moved into the field of clinical diagnostics. The company has expanded and refined its product range and now manufactures more than 1,000 clinical and research use products. The company s products are used by immunologists in more than 70 countries and its antisera production has increased to thousands of liters. Binding Site is located in San Diego, Calif.