laboratory diagnostic - hormones - fertility - 17-Hydroxy-Pregnenolone , Serum or EDTA Plasma or Heparin Plasma 2ml, refrigerated, CIRCADIAN RHYTHM: This biological parameter has a circadian rhythm (maximum concentration in morning), with a sufficiently significant amplitude to have a significant influence on the clinical interpretation, Chromatography - Extraction - Radioimmunoassay, ssso, todylaboratories®, bmn, code L16LD1812