High-Precision Estradiol Quantification for Reproductive Endocrinology & ART
The Sekbio E2 CLIA Bulk Reagent enables quantitative measurement of 17β-Estradiol — the primary estrogen critical for monitoring follicular development in ART/IVF, diagnosing menstrual disorders, evaluating menopausal status, and assessing estrogen-responsive conditions.
One-step sandwich format on the AE chemiluminescence platform. Range 7.27–3,889 pg/mL spans prepubertal through IVF peak concentrations. CV ≤2.2% meets the precision required for serial E2 monitoring during ovarian stimulation cycles.
Six calibrators from 7.27 to 3,889 pg/mL with inter-run CV 0.49–2.71% per level and S/N rising from 4.11 to 1,143.
| Calibrator (pg/mL) | RLU Run 1 | RLU Run 2 | RLU Run 3 | Avg RLU | CV% | S/N |
|---|---|---|---|---|---|---|
| 7.27 (Blank) | 2,007 | 2,043 | 2,063 | 2,038 | 1.25% | 1.00 |
| 16.92 | 8,520 | 8,199 | 8,428 | 8,382 | 2.71% | 4.11 |
| 24.89 | 13,584 | 13,489 | 13,673 | 13,582 | 0.49% | 6.67 |
| 161.15 | 100,099 | 101,887 | 99,775 | 100,587 | 1.26% | 49.4 |
| 1,949.84 | 1,181,401 | 1,201,039 | 1,191,031 | 1,191,157 | 1.17% | 585 |
| 3,889.28 | 2,299,810 | 2,361,666 | 2,323,179 | 2,328,218 | 1.88% | 1,143 |
| Blank limit (avg+2SD, n=20): 7.64 pg/mL. S/N = Avg RLU / Blank RLU. | ||||||
| QC Level (pg/mL) | Avg Conc (pg/mL) | SD (pg/mL) | CV |
|---|---|---|---|
| ~25 (Low) | 25.04 | 0.46 | 1.8% |
| ~163 (Mid) | 162.88 | 2.71 | 1.7% |
| n=10 replicates per level. Acceptance criterion: CV ≤10%. | |||
Serial E2 monitoring every 1–2 days guides gonadotropin dosing and trigger timing. 7–3,889 pg/mL and ≤2.2% CV enable precise follicular E2 tracking from basal to peak.
Blank limit 7.64 pg/mL accurately captures postmenopausal and POI concentrations for HRT initiation, dose adjustment, and POI diagnosis.
E2 in males (10–40 pg/mL) for gynecomastia, aromatase excess, and hypogonadism workup on the same CLIA platform as female panels.
Ra magnetic bead + Rd AE bulk pair for CLIA analyzer integration. Full validation package — calibration, precision, blank limit, method comparison — for regulatory submissions.
Estradiol (E2, 17β-estradiol) is the primary and most biologically active estrogen in humans. It is a C18 steroid hormone synthesized predominantly in the granulosa cells of ovarian follicles in women, and in lesser amounts by the testes and adrenal cortex in men via aromatisation of testosterone. Estradiol mediates its effects through estrogen receptors ERα and ERβ expressed in the uterus, breast, bone, cardiovascular system, liver, and brain. In IVD clinical testing, E2 measurement is central to fertility medicine (ART/IVF cycle monitoring), reproductive endocrinology (POI, menopause staging, menstrual disorder diagnosis), and male endocrine evaluation (gynecomastia, aromatase excess). Estradiol immunoassays use anti-E2 monoclonal antibodies with high specificity against 17β-estradiol and <1% cross-reactivity to estriol (E3) and estrone (E1).
| Life Stage / Status | Total Estradiol (pg/mL) | Clinical Significance |
|---|---|---|
| Women — Early follicular (Day 2–4) | 20–150 | Basal E2; >80 pg/mL suggests residual cyst or low ovarian reserve |
| Women — Mid-follicular | 30–300 | Rises 50–100% per 48 h per maturing follicle cohort |
| Women — Pre-ovulatory peak | 100–600 | Triggers LH surge; in ART, 150–300 pg/mL per dominant follicle |
| Women — Luteal phase | 60–300 | Corpus luteum production; low (<60) suggests luteal insufficiency |
| Women — Postmenopause | <35 | Predominantly from peripheral aromatisation; guides HRT initiation |
| Women — Pregnancy (3rd trimester) | 3,000–30,000+ | Placental origin; estriol (E3) rises more than E2 |
| Men — Adult normal | 10–40 | Derived from testicular and peripheral aromatisation of testosterone |
| Men — Elevated (gynecomastia threshold) | >60 | Evaluate for aromatase excess, testicular tumour, cirrhosis, obesity |
| Prepubertal children | <15 | Very low; requires LC-MS/MS or high-sensitivity CLIA for accuracy |
| Reference intervals are method- and laboratory-dependent. Values above are indicative ranges from CLIA immunoassay platforms calibrated to LC-MS/MS reference methods. | ||
The hormonal relationship between estrogen and Progesterone Antibody targets is essential for interpreting reproductive axis panels — FSH, LH, E2, and progesterone are commonly measured together in fertility and endocrine workups.
Yes — oestradiol is the British English spelling of estradiol. Both refer to 17β-estradiol (E2), the same hormone. IVD assay kits sold in the UK and EU markets often use the oestradiol spelling, while US and Asian kits use estradiol. The target analyte, antibody specificity, and clinical reference ranges are identical.
In women, E2 >600 pg/mL outside the pre-ovulatory window suggests ovarian hyperstimulation, an estrogen-secreting tumour, or obesity-driven aromatisation. In men, E2 >60 pg/mL is associated with gynecomastia. During IVF, E2 >3,000 pg/mL warrants OHSS risk assessment. Elevated E2 suppresses FSH, which is why FSH and estradiol are commonly ordered together.
Basal E2 (Day 2–3) should be <80 pg/mL. During stimulation, E2 should rise 50–100% every 48 hours per follicular cohort. At trigger, 1,500–4,000 pg/mL is typical for 3–5 mature follicles; >10,000 pg/mL is high-risk for OHSS. Reliable serial monitoring requires a CLIA platform with detection range 7–4,000 pg/mL and CV <5%.
An E2 blood test measures estradiol in serum or plasma collected by venepuncture. The sample is centrifuged within 30–60 minutes and analysed on an automated immunoassay analyser (CLIA, ECLIA) or by LC-MS/MS for low-concentration confirmatory testing. Whole blood cannot be analysed directly — serum separation is mandatory. Results are typically available within 2–4 hours in hospital lab settings.
FSH (follicle-stimulating hormone) and estradiol form a feedback pair that governs follicular recruitment. Low E2 at cycle Day 2–3 alongside elevated FSH (>10–12 IU/L) indicates diminished ovarian reserve. Conversely, high E2 with low FSH in a postmenopausal woman suggests exogenous estrogen use or an estrogen-producing tumour. The FSH:E2 ratio interpretation requires both markers to be drawn in the early follicular phase under standardised conditions.
Anti-E2 monoclonal antibodies for IVD use must achieve <1% cross-reactivity with estriol (E3) and estrone (E1), and <0.5% with testosterone and progesterone. Estriol specificity is particularly critical during pregnancy, where E3 concentrations can reach 5,000–30,000 pg/mL. All Sekbio E2 antibody pairs are characterised with full cross-reactivity panels to CLSI EP7 standards and include lot-specific certificates of analysis.
Full technical specifications, performance data, and OEM pricing available on request.