A Rapid Aldosterone Radioimmunoassay1

This laboratory previously reported a radioimmunoassay (RIA) for aldosterone based on prior purification by solvent partitioning, periodate oxidation and a single thin-layer chromatogram. Other methods reported to date require paper chromatography to attain the required specificity. The method presented herein utilizes antibodies produced to aldosterone-γ-lactone 3-carboxymethyl oxime coupled to BSA. Aldosterone-γ-lactone constitutes the ligand. Overall interference is: cortisol 0.07%, corticosterone 0.02%, progesterone 0.17%, estradiol-ND, testosterone 0.02%, and 18-hydroxy corticosterone 0.29%. The purification procedure consists of CHCI3 extraction, benzene:H2O partition, periodate oxidation and bicarbonate wash. Recovery is determined from added 3H- or 14Caldosterone and is 40–50%. Simultaneous GC and RIA of urine samples (μg/24 hr) are: The correlation between GC and RIA methods is 0.95% (p < .01). RIA values with and without TLC showed no significant difference. This method is simple and reproducibl...