ABSTRACT
Radioimmunoassay (RIA), since its discovery in 1956 by S.A Berson and R.S. Yalow, has significantly improved the sensitivity and ease of performing quantitative and specific analysis on important substances of biological interest. Separation of the free and bound fractions in RIA leads to shifts in binding depending on the separation method. Becton Dickinson Immunodiagnostics offers a new approach in automation that conserves valuable antibody in a recyclable process using ARIA II®. Versatility in automated RIA has been achieved with the ARIA II® system. Aria II® has the capability of counting tritium as well as gamma emitting isotopes. There are four types currently available on ARIA II®: simultaneous injection of tracer with sample, competitive protein binding assays, sequential injection of tracer and double first antibody. The use of double first antibody techniques has opened up new areas where sensitivity is a requirement.
