• Catalog Number K038-H
  • Assay Type Competitive ELISA
  • Sample Type Serum, Plasma, Urine, Fecal Extracts, Tissue Culture Media
  • Sensitivity 26.4 pg/mL
  • Species Estrone-3-sulfate (E1S) is identical across species
  • Assay Duration 2.5 Hours
  • Samples/Plate 40 in Duplicate
  • Readout Colorimetric, 450 nm


Assay Principle: 

The Estrone-3-Sulfate (E1S) ELISA Kit quantitatively measures E1S in serum, plasma, fecal extracts, urine, and tissue culture media. The Estrone-3-Sulfate (E1S) 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 E1S standard to generate a standard curve for the assay.

Protocol Summary:

  • Introduce standards or diluted samples into the provided transparent microtiter plate coated with goat anti-rabbit IgG antibody.
  • Add E1S peroxidase conjugate and E1S polyclonal rabbit antibody to each well, ensuring thorough mixing.
  • Incubate the mixture at room temperature, shaking for 2 hours. The immunological reaction is inversely proportional to the E1S concentration in the sample.
  • After incubation, wash away excess conjugate and add the TMB substrate. This substrate reacts with the bound conjugate to produce a measurable signal.
  • Use a plate reader to measure the signal at 450nm and calculate the E1S concentration based on the standard curve.


Estrone-3-sulfate (E1S) is a significant estrogen conjugate synthesized in the placental tissue. In nonpregnant women and normal men, E1S is present in the plasma at higher concentrations compared to unconjugated estrone or estradiol. This predominance is largely due to the conjugation of estrone and converted estradiol in non-glandular tissues, making E1S the most abundant circulating estrogen.

E1S plays an important role in various physiological and pathological processes. Breast tumors, for instance, exhibit sulfatase activity capable of converting E1S into estradiol. Thus E1S is a notable biomarker in oncology research. Additionally, E1S measurements have been suggested as diagnostic markers in conditions like cryptorchidism in horses, where undescended testicles affect reproductive capacity. The measurement of E1S, along with other hormones like testosterone, offers valuable diagnostic insights in such conditions.

The DetectX® Estrone-3-Sulfate (E1S) ELISA Kit is an essential tool for researchers and clinicians in endocrinology, reproductive biology, and oncology. It enables precise quantification of E1S in various biological samples, contributing to a better understanding of hormonal dynamics and their implications in health and disease.

Estrone-3-Sulfate (E1S) ELISA Kits

In Stock
1 Plate K038-H1
5 Plates K038-H5

Research Areas