A new specific and sensitive time resolved-fluoroimmunoassay of 11-deoxycortisol in serum.
A biotinylated 11-deoxycortisol tracer was synthesized from 11-deoxycortisol-3-carboxymethyloxime and the conjugate obtained by acylation of biotinylaminopropylammonium trifluoroacetate. This biotinylated tracer was used to develop an 11-deoxycortisol time-resolved-fluoroimmunoassay (TR-FIA). The tracer was quantified after adding streptavidine-Europium. A TR-FIA sensitive standard curve, with displacement of 20, 50, and 80% of tracer was obtained with 12.4, 70.7, and 512.8 pg of 11-deoxycortisol, respectively. After extraction followed by Celite chromatography, purified serum samples were simultaneously assayed by RIA and TR-FIA. The results obtained by the two methods were practically identical, however, this new specific, non-isotopic 11-deoxycortisol assay has the advantage of being more sensitive than RIA, thus well-suited to accurate measurement in endocrinological studies, particularly when serum 11-deoxycortisol levels in patients are just above the highest normal values. Moreover, this non-isotopic assay is cheaper than RIA.
Fiet
J
J
Laboratoire d'Hormonologie, Hôpital Saint-Louis, 1 Avenue Claude Vellefaux, 75475 Paris Cedex 10, France. jean.fiet@libertysurf.fr
Giton
F
F
Boudou
P
P
Villette
J M
JM
Soliman
H
H
Morineau
G
G
Boudi
A
A
Galons
H
H
D003350:Cortodoxone / Q000097:blood* / Q000276:immunology; D005455:Fluorescent Antibody Technique; D006801:Humans; D007106:Immune Sera; D009682:Magnetic Resonance Spectroscopy; D011863:Radioimmunoassay; D012680:Sensitivity and Specificity
D007106:Immune Sera; D003350:Cortodoxone