Research Areas



  • Assay Type Competitive ELISA
  • Sample Types Saliva, Urine, Fecal Extracts, Extracted Serum, Extracted Plasma, Tissue Culture Media
  • Sensitivity 5.33 pg/mL
  • Species Estriol is identical across species
  • Assay Duration 2.5 Hours or Overnight
  • Samples/Plate 38 in Duplicate
  • Readout Colorimetric, 450 nm
  • Standard Curve Estriol ELISA Kit
  • Description

    Assay Principle: 

    The Estriol ELISA Kit quantitatively measures Estriol in saliva, urine, extracted serum, extracted plasma, fecal extracts, and tissue culture media. The Estriol ELISA Kit is a competitive ELISA with a run time of 2.5 hours. Please read the complete kit insert for more information before performing this assay.

    Use our provided Estriol standard to generate a standard curve for the assay. Pipette the standards or diluted samples into a transparent microtiter plate coated with our goat anti-rabbit IgG antibody. Add the Estriol peroxidase conjugate and the Estriol rabbit polyclonal antibody. Then incubate the mixture covered at room temperature, shaking for 2 hours. The immunological reaction occurs between the anti-Estriol antibody, the Estriol antigen in the sample or standard, and the Estriol conjugate. As the Estriol concentration in the sample increases, the bound Estriol-peroxidase conjugate decreases, causing a decrease in signal and vice versa. 

    After the 2-hour incubation, wash away the excess Estriol-peroxidase conjugate and add the TMB substrate. The TMB substrate reacts with the bound Estriol-peroxidase conjugate generating a signal detected by a plate reader at 450nm. Use the intensity and the standard curve to calculate the Estriol concentration in the samples.


    Estriol is one of the three major endogenous estrogens, including estradiol and estrone. It is a weak estrogen derived from the hydroxylation of estradiol and estrone in the liver. Average levels in women who are not pregnant are typically nearly undetectable. However, the placenta produces Estriol in large amounts, and physicians monitor rising maternal levels from the very early weeks of pregnancy until delivery. Physicians monitor Estriol as an indicator of fetal health and well-being during pregnancy. Physicians routinely measure Estriol as part of the triple and quadruple tests during pregnancy outreach and screening. Abnormally low levels in pregnant females can suggest fetal chromosomal or congenital anomalies. In some parts of the world, exogenous Estriol treats menopausal symptoms. Investigators hypothesize that Estriol is a protective neurosteroid with potential roles in immune diseases and bone and lipid metabolism.

  • Structure