The SDi Total Estrogens ELISA kit is intended for the quantitative determination of human Estrogens (e1, E2 & E3) levels in human serum or Plasma.
Estrogens are 18-carbon steroids secreted by the gonads, adrenal glands, and placenta. The principal estrogens are estradiol (E2), estrone (E1), and estriol (E3). E2 is the major estrogen produced by the ovaries. E1 is derived from ovarian secretion and peripheral conversion from gonadal and adrenal androstenedione. E3 is produced in the liver by metabolism from E2. The placenta produces all of these estrogens.
Principle of the Test
The SDi Total Estrogens ELISA kit is based on the principle of competitive binding between Estrogens in the test specimen and enzyme labeled estrogens for a constant amount of rabbit anti-estrogens antibody. In the first incubation, goat anti-rabbit IgG-coated wells are incubated with 50μl of Total Estrogens standards, controls, patient samples, 100μl Estrogens-HRP conjugate reagent and 50μl rabbit anti-Total Estrogens reagent, at room temperature, for 120 minutes, with agitation. During the incubation, HRP labeled Total Estrogens competes with the endogenous estrogens in the standard, controls and sample, for a fixed number of binding sites of the specific anti Total Estrogens antibody. Thus, the amount of HRP labeled Estrogens conjugate immunologically bound to the antibody progressively decreases as the concentration of Total Estrogens in the specimen increases. Unbound Total estrogens enzyme conjugate is then removed and the wells washed. Then substrate (TMB) reagent is added and incubated, with agitation, for 30 minutes, resulting in the development of blue color. The color development is stopped with the addition of 50µL stop solution, and the absorbance is spectrophotometrically measured at 450nm. A standard curve is prepared relating color intensity to the concentration of Total Estrogens versus the absorbance.