96 Wells
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Product Name: Total Estriol

# of Samples: 1 x 96 Assays

Intended Use: Competitive immunoenzymatic colorimetric method for quantitative determination of Estriol in serum or plasma.

Introduction: Estriol is a female sex steroid hormone and one of the three major naturally occurring estrogens, the others being estradiol and estrone. Estriol is produced almost exclusively during pregnancy and is the major estrogen produced in the normal human fetus. During pregnancy the production of Estriol depends on an intact maternal-placental-fetal unit. Fetal-placental production of Estriol leads to a progressive rise in maternal circulating levels reaching a late-gestational peak several orders of magnitude greater than non-pregnant levels. In non-pregnant circumstances, Estriol is derived almost exclusively from 17 β-Estradiol. Estriol exists in biological matrix in free (ca. 9 %) and conjugated form (91 %). Conjugation with glucuronic or sulphuric acid of estriol occurs in the liver, which aides in steroid solubility, therefore allowing rapid elimination via the kidney.

Principles of the assay: Microtiter strip wells are precoated with anti-Estriol antibodies (solid-phase). Estriol in the sample competes with added horseradish peroxidase labelled Estriol (enzyme-labelled antigen) for antibody binding. After incubation a bound/free separation is performed by solid-phase washing. The immune complex formed by enzyme-labelled antigen is visualized by adding Tetramethylbenzidine (TMB) substrate which gives a blue reaction product. The intensity of this product is inversely proportional to the amount of Estriol in the sample. Sulphuric acid is added to stop the reaction. This produces a yellow endpoint colour. Absorption at 450 nm is read using an ELISA microwell plate reader.

Storage and Stability: The reagents are stable up to the expiry date stated on the label when stored at 2...8 C in the dark.

Limitations of the Test: Bacterial contamination or repeated freeze-thaw cycles of the specimen may affect the absorbance values.

References Fisher-Rasmussen, W., Gabrielsen, M. V. and Wisborg (1981) Acta Obstet. Gynecol Scand 60, 417 - 420.Truran, P. L., Read, G.F. and Walker, S. (1982) Clin. Chem. 28 (12), 2393.Vining, R. F., Mc Ginley, R. and Rice B. (1983) J. Clin. Endoc. Metab. 56, 454.Bagger, P. V., Jacobsson, K. and Gullberg, B. (1981) Acta Obstet Gynecol Scand 60, 187.Osterman, T. M., Juntunen, K.O. and Gothoni, G.D. (1979) Clin. Chem. 25 (5), 716.Wisdom, G.B. (1976) Clin Chem. 22 (8), 1243-1255.

Additional Information

Related Product Names Total Estriol
Molecular Weight 0.5
Storage The reagents are stable up to the expiry date stated on the label when stored at 2...8 C in the dark.
Datasheets/Manuals Printable manual for GWB-1FCEC3
Intended Use Research Use Only