A Radioimmunoassay for Serum and Urine Aldosterone by Celite Column Chromatography

A relatively simple and rapid radioimmunoassay (RIA) for the measurement of aldosterone in serum and urine has been developed. The method involves extraction of 1 ml of serum or urine (after acid hydrolysis) with dichloromethane, followed by partition chromatography on celite microcolumns prior to RIA. Dextran coated charcoal is used for separation of free from antibody-bound aldosterone. The method is very sensitive, blanks are negligible and recovery is approximately The%. 80 coefficient of variation is 4. 3% (within assay) and 10. 4% (between assay). When known amounts of aldosterone were added to serum and urine pools containing low endogenous levels of this steroid recovery was quantitative. Aldosterone concentrations measured under various physiological conditions were in agreement with published data. Up to 150 samples can be assayed by 1 technician during 5 working days.