Description
Introduction: Estradiol (E2 or 17beta-estradiol) (also oestradiol) is a sex hormone. During the reproductive years, most estradiol in women is produced by the granulosa cells of the ovaries by the aromatization of androstenedione (produced in the theca folliculi cells) to estrone, followed by conversion of estrone to estradiol by 17beta-hydroxysteroid reductase. Smaller amounts of estradiol are also produced by the adrenal cortex, and (in men), by the testes. Estradiol is not only produced in the gonads: in both sexes, precursor hormones, specifically testosterone, are converted by aromatization to estradiol. In particular, fat cells are active to convert precursors to estradiol, and will continue to do so even after menopause. Estradiol is also produced in the brain and in arterial walls. Estradiol enters cells freely and interacts with a cytoplasmic target cell receptor. When the estrogen receptor has bound its ligand it can enter the nucleus of the target cell, and regulate gene transcription which leads to formation of messenger RNA. The mRNA interacts with ribosomes to produce specific proteins that express the effect of estradiol upon the target cell. Estradiol binds well to both estrogen receptors, ERalpha and ERbeta, in contrast to certain other estrogens, notably medications that preferentially act on one of these receptors. These medications are called selective estrogen receptor modulators, or SERMs.
Principle of the Assay: The microtiter plate provided in this kit has been pre-coated with an goat-anti-rabbit antibody. Standards or samples are then added to the appropriate microtiter plate wells with a HRP-conjugated Estradiol and antibody preparation specific for Estradiol and incubated. Then a TMB (3,3',5,5' tetramethyl-benzidine) substrate solution is added to each well. The enzyme-substrate reaction is terminated by the addition of a sulphuric acid solution and the color change is measured spectrophotometrically at a wavelength of 450 nm } 2 nm. The concentration of Estradiol in the samples is then determined by comparing the O.D. of the samples to the standard curve