MODULATION OF THE MEASURING RANGE OF A RADIOIMMUNOASSAY USING AN ORGANIC-WATER 2 PHASE SYSTEM

A commercially available radioimmunoassay (RTA) kit was used to study the effects of organic solvents on antigen-antibody interactions. The RIA analysis was carried out in aqueous-organic two phase systems. Aft er exposure to hydrophobic organic solvents the antibodies retained fu ll binding capacity, while less hydrophobic solvents caused partial in activation of the antibodies. A practical analysis for digoxigenin in organic solvents was developed using the RIA kit with polyclonal antib odies against digoxin. The sensitivity was modulated four orders of ma gnitude by the choice of organic solvent. The main factor influencing the sensitivity was the partitioning of digoxigenin between the aqueou s and the organic phases. The technique developed is promising for the analysis of a variety of antigens dissolved in organic solvents.