Radioimmunoassay (RIA) is a very sensitive in vitro assay technique used to measure concentrations of antigens (for example, hormone levels in blood) by use of antibodies. As such, it can be seen as the inverse of a radiobinding assay, which quantifies an antibody by use of corresponding antigens. Although the RIA technique is extremely sensitive and extremely specific, requiring specialized equipment, it remains among the least expensive methods to perform such measurements.
Everything American Express is offering during the US Open this year is designed to enhance what tennis fans love about this tournament, said Deborah Curtis, vice president of entertainment and sports marketing at American Express.
2016 US Open Tennis Tickets. 2016 U.S. Open Tennis tickets are on sale now for all sessions including the feature matches at Arthur Ashe Stadium in Flushing Meadows, New York. The 2016 U.S. Open Tennis Tournament is the final event of the four major tennis events that make up the Grand Slam.