The Journal of Clinical Endocrinology & Metabolism · 1972 · 330 citations · 0 references
MedicineEndocrinologyClinical BiochemistryNeuroendocrinologyPsychoneuroimmunologyAdrenal EndocrinologyAdrenal HormonesEndocrine AssessmentEndocrine DiagnosticsEndocrine TestingHormonal EvaluationBovine Serum AlbuminEndocrine Laboratory DiagnosticsSerum Cortisol MeasurementStandard Curve ConstructionUrinary CortisolUrinary Hormone Measurement
ABSTRACT A radioligand assay for the measurement of cortisol in plasma and urine has been developed. Antibodies raised against cortisol-21-hemisuccinate conjugated to bovine serum albumin had a high affinity for cortisol (K = 2 × 109 1/mole). A standard curve was established with a useful range from 0.10–4.0 ng. Plasma cortisol is readily measured by directly assaying small aliquots of a methylene chloride extract of plasma. Urine free cortisol was assayed after a single TLC of a methylene chloride extract of urine. Intraassay variability of both urine and plasma cortisol determinations was 10%; interassay variability was 20–26%. This method is particularly useful for measurement of 24-hr urine free cortisol.