Yanda Bio presents a robust and ready-to-use Human Estrone-3-sulfate (E3S) ELISA kit for the accurate quantification of this major circulating estrogen conjugate in human serum, plasma, cell culture supernatant, and tissue homogenates. With a portfolio of over 6,000 validated ELISA targets covering human, mouse, rat, horse, rabbit, canine, bovine, chicken, duck, sheep, monkey, fish, insect, plant, and microbial species, we are the trusted partner for more than 60 universities and research institutes across China. Our kits are recognized for high reproducibility, strong specificity, and excellent sensitivity—with custom sensitivity configurations available. Enjoy free shipping when you buy any 3 kits, and unlock our complimentary elisa testing service: our professional lab will run the assay on your samples, video‑record the complete procedure, and deliver all raw data at no additional charge. If you need enhanced sensitivity, ask about our NHS‑biotin‑amplified ELISA kits. We also provide rigorous immunogenicity elisa testing services for preclinical therapeutic evaluation. This kit is validated for human samples exclusively.
Why Quantify Human Estrone-3-sulfate?
Estrone-3-sulfate (E3S) is the most abundant circulating estrogen conjugate, acting as a long‑lived precursor pool that can be desulfated locally by steroid sulfatase (STS) to yield active estrone and estradiol. Unlike routine estradiol or estrone measurements that capture acute fluctuations, E3S provides a stable, integrated index of estrogen metabolism. Key research applications for this human E3S ELISA test include:
- Pharmacological transporter inhibition studies: E3S is a well‑characterized substrate of organic anion‑transporting polypeptides (OATPs, particularly OATP1B1 and OATP1B3). Quantifying E3S uptake or serum levels is a gold‑standard approach for evaluating drug‑transporter interactions, hepatic clearance mechanisms, and OATP‑mediated drug‑drug interaction potential. This E3S ELISA kit enables rapid, high‑throughput readouts without radiometric methods.
- Breast cancer endocrine metabolism research: Intratumoral conversion of E3S to active estrogens via STS sustains estrogen receptor‑positive breast cancer growth. Monitoring E3S levels in tumor homogenates or serum helps investigate endocrine resistance, STS inhibitor efficacy, and paracrine estrogen signaling.
- Placental endocrinology: The placenta exhibits high sulfotransferase activity, making E3S a valuable marker for studying fetoplacental steroidogenesis.
Important research note: This assay is designed for pharmacological and mechanistic investigations. For routine clinical assessment of hormonal status, dedicated estradiol or estrone immunoassays should be used.
Assay Principle – One‑Step Sandwich ELISA
The kit employs a double‑antibody one‑step sandwich enzyme‑linked immunosorbent assay (ELISA). The microplate wells are pre‑coated with an antibody specific for estrone‑3‑sulfate (E3S) . Standards, samples, and an HRP‑labeled detection antibody are added sequentially to the wells. After incubation and thorough washing, TMB substrate is introduced. TMB is converted to a blue color by the peroxidase and turns yellow upon addition of the stop solution. The color intensity is positively correlated with the concentration of estrone‑3‑sulfate (E3S) in the sample. The absorbance (OD value) is measured at 450 nm using a microplate reader, and the sample concentration is calculated.
Kit Components
| Component | 96‑Well Format | 48‑Well Format | Remarks |
|---|---|---|---|
| Pre‑coated Microplate | 12 strips × 8 wells | 12 strips × 4 wells | Ready to use |
| Standard (S0–S5) | 0.3 mL × 6 tubes | 0.3 mL × 6 tubes | Concentrations: 0, 40, 80, 160, 320, 640 pg/mL |
| Sample Diluent | 6 mL | 3 mL | – |
| Detection Antibody‑HRP | 10 mL | 5 mL | – |
| 20× Wash Buffer | 25 mL | 15 mL | Dilute before use |
| Substrate A | 6 mL | 3 mL | – |
| Substrate B | 6 mL | 3 mL | – |
| Stop Solution | 6 mL | 3 mL | – |
| Plate Sealers | 2 sheets | 2 sheets | – |
| Instruction Manual | 1 copy | 1 copy | – |
| Self‑sealing Bag | 1 piece | 1 piece | For unused strip storage |
The S0 zero standard serves as the blank/negative control.
Performance Characteristics
| Parameter | Specification |
|---|---|
| Detection Range | 1.0 – 400 pg/mL |
| Analytical Sensitivity | < 1.0 pg/mL |
| Accuracy | Standard curve R ≥ 0.9900 |
| Precision | Intra‑assay CV < 15%; Inter‑assay CV < 15% |
| Specificity | Recognizes human E3S; no cross‑reactivity with estrone, estradiol, estriol, or their glucuronides |
| Validated Sample Types | Human serum, plasma (EDTA/citrate/heparin), cell culture supernatant, tissue homogenate |
| Shelf Life | 6 months at 2–8°C, protected from light |
For ultra‑low E3S concentrations, inquire about our NHS‑biotin‑enhanced ELISA kits for improved signal amplification.
Free ELISA Testing Service – We Run the Assay for You
When you purchase this kit, you gain access to Yanda Bio’s free elisa testing service. Simply ship your prepared human samples to our facility, and our expert technicians will:
- Process and load your samples according to the validated protocol
- Execute the entire ELISA with precise incubation, washing, and detection
- Record the full experiment on video for complete transparency
- Provide raw OD values, the standard curve, and final E3S concentrations in an Excel file
This hands‑off approach saves instrument time, eliminates optimization burdens, and is ideal for high‑throughput drug‑transporter studies or multi‑cohort breast cancer research. We also offer standalone immunogenicity elisa testing services with detailed documentation to support biologic development programs.
Sample Collection & Preparation
- Serum: Collect blood in endotoxin‑ and pyrogen‑free tubes, allow to clot, centrifuge at 3000 rpm for 10 min, and separate the serum.
- Plasma: Use EDTA, citrate, or heparin. Centrifuge at 3000 rpm for 30 min and collect the supernatant.
- Cell Culture Supernatant: Spin at 3000 rpm for 10 min to remove cells and debris.
- Tissue Homogenate: Homogenize tissue (e.g., breast tumor, placenta) in normal saline, centrifuge at 3000 rpm for 10 min, and keep the supernatant.
- Storage: Aliquot samples and store at -20°C if not tested immediately. Avoid repeated freeze‑thaw cycles. Thaw completely at room temperature and mix gently before use.
Species specificity: This kit is validated exclusively for human samples and should not be used with animal specimens.
Brief Assay Protocol
Full instructions are included with the kit. Summary:
- Equilibrate all reagents and pre‑coated strips to room temperature for 20 min.
- Add 50 µL of each standard to the designated wells. For sample wells, add 10 µL sample + 40 µL sample diluent (5‑fold dilution). Leave blank wells empty.
- Add 100 µL HRP‑Detection Antibody to all wells except blanks. Cover and incubate at 37°C for 60 min.
- Wash 5 times with 1× wash buffer (dilute 20× concentrate; dissolve crystals by warming). Soak 1 min per wash, then blot dry.
- Add 50 µL Substrate A and 50 µL Substrate B. Incubate in the dark at 37°C for 15 min.
- Add 50 µL Stop Solution. Read OD at 450 nm within 15 min. Construct the standard curve and multiply the obtained value by 5 to get the actual sample concentration.
Required Equipment (not supplied)
- Microplate reader (450 nm)
- Precision pipettes (0.5‑10, 2‑20, 20‑200, 200‑1000 µL)
- 37°C incubator or water bath
- Deionized water, graduated cylinders, absorbent paper
Expand Your Estrogen Research Panel
Pair this human E3S ELISA kit with the following assays for a comprehensive endocrine metabolism analysis:
- Human Estrone (E1) ELISA Kit – quantify the unconjugated parent estrogen that is released from E3S by steroid sulfatase.
- Human Estradiol (E2) ELISA Kit – measure the most potent natural estrogen to evaluate the endpoint of the sulfatase pathway.
Explore our full range of steroid hormone, SHBG, and transporter‑related ELISA kits.
Why Choose Yanda Bio
- Unmatched diversity: Over 6,000 validated ELISA,targets across humans, rats, mice, rabbits, pigs, cattle, fish, microorganisms and insects Elisa kit 15+ species.
- Proven performance: Kits are highly reproducible, specific, and sensitive, with custom sensitivity options.
- Academic trust: Long‑term collaborations with 60+ universities in China.
- Free shipping: On any order of 3 kits.
- Complimentary elisa testing service: We run the assay, provide a video, and deliver all data at no cost.
- High‑sensitivity options: NHS‑biotin‑amplified kits available for ultra‑low detection.
- Immunogenicity testing: Dedicated immunogenicity elisa testing services for anti‑drug antibody evaluation.
Disclaimer: This kit is for research use only and is not intended for clinical diagnosis or therapeutic decision‑making. For clinical hormonal assessment, standard estradiol or estrone tests should be employed. This human E3S ELISA kit is validated for human samples only and must not be used with non‑human specimens. Follow the protocol exactly; any deviations are the responsibility of the experimenter. Yanda Bio shall not be liable for consequences arising from improper use.
Yanda Bio – Precision ELISA Kits, Expert elisa testing service, and immunogenicity elisa testing services for your endocrine pharmacology and oncology research.
