Sensitivity and Specificity of Prostanoic Derivatives Radioimmunoassays: New Approach

Abstract

Prostanoic derivatives, as prostaglandin, thromboxane, prostacyclin and their metabolites, are generally present in biological media at very low concentrations (10^-9–10^-11 M). Therefore assays with high sensitivity often are required for their measurement. Two techniques are widely used: mass spectrometry combined with gas chromatography (GS-MS), which is particularly specific (1) and radio-immunoassay (RIA) which particularly sensitive and convenient for large series (2, 7). In our laboratory, immunological methods have been developed using radioactive (8) or non-radioactive tracers (5, 9); iodinated derivatives (as PG-¹²⁵ I-Histamine) have been shown to be more sensitive and convenient (10–14). In this paper some aspects of the use of iodinated tracers will be presented and a new approach for increasing the specificity of prostanoic derivatives will be proposed.