Time-resolved fluoroimmunoassay for unconjugated estrogen in urine: comparison with a fluorometric assay for total estrogen and application in an in vitro fertilization program.
A time-resolved fluoroimmunoassay (TR-FIA) for unconjugated estrogens in human urine is described. 6-Keto-17 beta-estradiol-6-(O-carboxymethyl)oxime:bovine serum albumin is immobilized onto microtiter strip wells and the coated wells are incubated with 17 beta-estradiol standard preparations or unknowns with a polyclonal antiserum to 17 beta-estradiol-16,17-monosuccinyl:albumin. The antiserum-bound estrogen is detected by incubation with a europium-labeled anti-rabbit IgG that serves as both second antibody and tracer. After the immunoreactions, the bound portion of the labeled antiserum is quantified by dissociating the Eu3+ in a fluorescence-enhancement solution and measuring its fluorescence with a time-resolved fluorometer. The detection limit of the TR-FIA is 24 pmol of 17 beta-estradiol per liter; the analytical range extends to 1.8 nmol/L. This assay is a convenient alternative to radioimmunoassay and to the automated Kober-Ittrich fluorometry of total estrogen. Its advantages include short counting times; use of nonradioactive, stable reagents, all of which are commercially available; and more nearly complete automation. We conclude that this TR-FIA, compared with the Kober-Ittrich fluorometric assay (J Endocrinol 1957; 16:49-56), provides the clinician with equivalent information during follicular development therapy as part of an in vitro fertilization program.
Thomas
C M
CM
Department of Obstetrics & Gynaecology, Sint-Radboud University Hospital, Nijmegen, The Netherlands.
van den Berg
R J
RJ
Segers
M F
MF
Geelen
L M
LM
Hollanders
J M
JM
Doesburg
W H
WH
Houx
P C
PC
D001322:Autoanalysis; D004967:Estrogens / Q000652:urine*; D005260:Female; D005307:Fertilization in Vitro; D015200:Fluoroimmunoassay; D005470:Fluorometry; D005498:Follicular Phase; D006801:Humans; D010062:Ovulation Induction
D004967:Estrogens