Estrone (also oestrone) is an estrogenic hormone secreted by the ovary. Estrone is one of the three estrogens, which also include estriol and estradiol. Estrone is the least prevalent of the three hormones, estradiol being prevalent almost always in a female body, estriol being prevalent primarily during pregnancy. Estrone sulfate acts as a pool of estrone which can be converted as needed to the more active estradiol. In pre-menopausal adult women, more than 50% of estrone is secreted by the ovary. In pre-pubertal children, men and postmenopausal women, the major portion of estrone is derived from peripheral tissue conversion of androstenedione. During pregnancy, large amounts of estrone are synthesized in the placenta from dehydroepiandrosterone sulfate (DHEA-S) which originates from the maternal circulation and from the fetal adrenal gland.

In pre-menopausal women, estrone levels generally parallel those of estradiol, rising gradually during the follicular phase, peaking just prior to ovulation, with a secondary and smaller increase during the luteal phase. After menopause, estrone levels do not decline as dramatically as estradiol levels, possibly due to increased conversion of androstenedione to estrone.

May be diagnosed by:

• Determination of specific antibodies based on the ELISA technique
• Determination of specific antibodies based on the RIA-technique

Estrone ELISA:

The Estrone ELISA is intended for competitive immunoenzymatic colorimetric method for quantitative determination of Estrone in human serum or plasma.

Principle of the Assay:

Microtiter strip wells are precoated with anti-Estrone antibodies (solid-phase). Estrone in the sample competes with added horseradish peroxidase labelled Estrone (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 Estrone 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.

Specific performance characteristics: 

Correlation with RIA performed on 50 samples is r = 0.96

Order information: