CHEMICAL PRECIPITATION TECHNIQUES FOR THE RADIOIMMUNOLOGIC QUANTITATION OF GONADOTROPHINS WITH SPECIAL REFERENCE TO THE ORGANIC SOLVENT DIOXANE

Abstract

A brief survey of the literature reveals that, for the radioimmunoassay of hormones, separation of free from antibody-bound hormone has been accomplished by increasing salt concentration (salting-out), precipitation with organic solvents (primarily ethanol) or combinations of both. The application of these techniques has been most successful with hormones in a relatively low protein milieu such as urine or buffers (standard curve analysis) but are somewhat limited for use on high protein mixtures such as plasma or serum. A detailed account of a technique involving precipitation of hormoneantibody complexes with the organic solvent dioxane is given. This technique has been most successfully applied to the quantitation of luteinizing hormone (LH) in plasma as well as in urine. A discussion of the problems encountered due to the specificity of the antibody and purity of tracer antigens (hormones), in the radioimmunoassay procedure for luteinizing hormone, is included.