Testosterone Sheep Monoclonal Antibody for Competitive CLIA & LFA IVD Development
Testosterone is the principal androgenic steroid hormone in humans, with a molecular weight of 288 Da (molecular formula C₁₉H₂₈O₂). In males, testosterone is predominantly synthesised by the Leydig cells of the testes at a rate of approximately 5–7 mg/day; in females, smaller quantities are produced by the ovaries and adrenal cortex. In serum, testosterone exists in three fractions: free testosterone (~2%), which is the biologically active form; sex hormone-binding globulin (SHBG)-bound testosterone (~58%); and albumin-bound testosterone (~40%). Clinical reference ranges are: males 300–1000 ng/dL (10.4–34.7 nmol/L) and females 15–70 ng/dL (0.5–2.4 nmol/L), though ranges vary by assay method and laboratory.
The clinical indications for testosterone measurement are broad and of high diagnostic importance. In males, total testosterone below 300 ng/dL is the primary diagnostic criterion for hypogonadism (testosterone deficiency syndrome), a condition affecting 2–4% of men aged 40–79. Testosterone testing is also central to male infertility evaluation, androgen replacement therapy monitoring, and differentiation of primary from secondary hypogonadism. In females, testosterone measurement supports the diagnosis of polycystic ovary syndrome (PCOS) — the most prevalent endocrine disorder in women of reproductive age, affecting 8–13% globally — as well as congenital adrenal hyperplasia (CAH), virilising adrenal or ovarian tumours, and gender-affirming hormone therapy monitoring. Sports medicine and anti-doping programmes rely on urinary testosterone-to-epitestosterone (T/E) ratio assays as a front-line doping detection tool.
For IVD immunoassay development, testosterone presents a fundamental technical challenge: at 288 Da, it is a small-molecule steroid hormone incapable of simultaneously binding two antibodies. Sandwich immunoassay formats, which require two spatially distinct epitopes, are therefore not applicable. Competitive immunoassay is the required format for all testosterone CLIA and LFA platforms: patient sample testosterone and a defined quantity of labelled testosterone (or testosterone conjugate) compete for a fixed, limited number of antibody binding sites; signal output is inversely proportional to sample testosterone concentration. Sekbio supplies two sheep-source anti-testosterone monoclonal antibodies — S01-T-1S and Testo-W251S — specifically characterised for competitive CLIA and LFA assay development, offering high selectivity for testosterone with low cross-reactivity to structurally related androgens such as DHEA-S and androstenedione.
Two sheep anti-testosterone monoclonal antibodies for competitive CLIA and LFA immunoassay development.
| Catalog No. | Product Name | Source | Purity | Intended Use | Storage |
|---|---|---|---|---|---|
| S01-T-1S | Sheep Anti-Human Testosterone Monoclonal Antibody | Sheep | ≥95% SDS-PAGE | Competitive Immunoassay — CLIA, LFA | −20°C long-term |
| Testo-W251S | Testosterone Antibody (Sheep Anti-Testosterone mAb) | Sheep | ≥95% SDS-PAGE | Competitive Immunoassay — CLIA, LFA | −20°C long-term |
All products supplied in PBS pH 7.4. MOQ 1 mg. OEM quantities (10 mg–gram scale) available. Lot E06001 available for Testo-W251S. Contact info@sekbio.com for bulk pricing and technical documentation.
Engineered for the selectivity and sensitivity required in clinical hypogonadism diagnosis, PCOS evaluation, and competitive immunoassay platform development.
Produced in sheep — an uncommon host species — Sekbio's testosterone antibodies offer distinct immunological characteristics compared to mouse or rabbit-derived antibodies. The sheep immune response to hapten-carrier conjugates often yields antibodies with high affinity and selectivity profiles well-suited to competitive steroid hormone assays, where discrimination from structurally similar androgens (DHEA-S, androstenedione, DHT) is critical for clinical accuracy.
Both S01-T-1S and Testo-W251S are specifically characterised for competitive immunoassay formats. Testosterone (288 Da) cannot support sandwich format; competitive CLIA and competitive LFA are the only viable platforms. Sekbio's antibodies are optimised for competitive assay kinetics — providing the right affinity constant range to achieve the sensitivity (LOD <0.1 ng/mL) and dynamic range (0.1–15 ng/mL) required for clinical testosterone quantification in both male and female reference intervals.
Both antibody lots are validated for competitive CLIA (high-sensitivity quantitative automated analyzer platforms for hospital laboratories) and competitive LFA (lateral flow rapid test strips for point-of-care and field use). This enables a single raw material source to support both laboratory quantitative testosterone testing and near-patient testosterone screening with a rapid test format, serving distinct market segments from a unified supply chain.
Both testosterone antibody products achieve ≥95% purity by SDS-PAGE analysis. Higher purity reduces non-specific signal in competitive immunoassays, where even low-level impurities can shift the competition equilibrium and degrade assay precision. Each lot ships with a full Certificate of Analysis documenting purity, appearance, and functional activity results. ISO 13485 QMS ensures batch-to-batch consistency for OEM production reliability.
Testosterone assays are clinically required across multiple diagnostic categories: male hypogonadism (testosterone <300 ng/dL), female PCOS (elevated free androgen index), infertility evaluation in both sexes, CAH monitoring, and androgen-secreting tumour diagnosis. Sekbio's high-specificity sheep mAbs ensure accurate testosterone quantification across the wide clinical concentration range from female low-normal levels (>15 ng/dL) through to male hypogonadal thresholds and normal supraphysiological ranges.
Sekbio supplies testosterone antibodies to IVD OEM manufacturers globally, from 1 mg R&D evaluation quantities to gram-scale production volumes. ISO 13485-compliant manufacturing in Shenzhen, China. Full regulatory documentation support for CE, NMPA, and FDA 510(k) submissions. Testosterone POCT and CLIA assay kits are in high demand in reproductive medicine clinics, endocrinology departments, and sports medicine programmes across Europe, North America, and the Asia-Pacific region.
Sheep anti-testosterone monoclonal antibody validated for competitive immunoassay kit development across endocrinology, reproductive medicine, and sports medicine.
Male hypogonadism (testosterone deficiency syndrome) is defined by total serum testosterone below 300 ng/dL combined with clinical symptoms (reduced libido, fatigue, erectile dysfunction, loss of muscle mass). Endocrine Society guidelines recommend morning total testosterone measurement as the initial diagnostic test, with confirmation on a second sample. Competitive CLIA platforms represent the current gold standard for clinical testosterone quantification in hospital andrology and endocrinology laboratories. Sekbio's S01-T-1S and Testo-W251S antibodies support high-sensitivity competitive CLIA kit development targeting this high-volume clinical indication.
Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women of reproductive age, affecting 8–13% of women globally. Biochemical hyperandrogenism — elevated serum total testosterone or free androgen index (FAI) — is one of the three Rotterdam diagnostic criteria. Competitive testosterone immunoassays are the most widely used screening tool for androgen excess in PCOS. Accurate quantification in the female reference range (15–70 ng/dL) requires high-sensitivity antibodies with minimal cross-reactivity to DHEA-S and androstenedione, both of which are elevated in PCOS. Sekbio's sheep mAbs are characterised specifically for this low-concentration female range.
Testosterone is a key biomarker in both male and female fertility workups. In males, testosterone measurement is part of the standard investigation of azoospermia and oligospermia, differentiating primary (testicular) from secondary (pituitary/hypothalamic) causes. In females, elevated testosterone contributes to anovulatory infertility in PCOS. Testosterone measurement is also included in pre-IVF ovarian reserve assessments and in the evaluation of diminished ovarian reserve. Competitive LFA testosterone rapid tests developed using Sekbio's antibodies support point-of-care fertility screening in reproductive medicine clinics and fertility treatment centres globally.
Testosterone competitive LFA rapid tests are a growing product category serving reproductive medicine POC testing, sports doping screening, and hypogonadism community diagnosis. Sekbio supplies sheep anti-testosterone mAbs (S01-T-1S and Testo-W251S) for OEM lateral flow strip development in competitive format. Compatible with colloidal gold and fluorescent microsphere labelling strategies. ISO 13485 batch data supplied for all lots. OEM manufacturers developing testosterone POC products for CE-marked, NMPA, or FDA-cleared diagnostics can contact info@sekbio.com for technical support. See our Products page and Platforms page for related antibody and assay development services.
Technical and commercial questions from IVD R&D engineers and procurement teams developing competitive testosterone immunoassays.
Testosterone is the primary androgenic steroid hormone, molecular weight 288 Da (C₁₉H₂₈O₂). In males it is produced mainly by testicular Leydig cells (5–7 mg/day); in females by the ovaries and adrenal glands. Serum testosterone is the primary biomarker for hypogonadism diagnosis (males: total testosterone <300 ng/dL), polycystic ovary syndrome (PCOS) in females, fertility evaluation, CAH monitoring, gender-affirming therapy monitoring, and anti-doping testosterone/epitestosterone (T/E) ratio testing. It is one of the highest-volume steroid hormone tests performed in clinical laboratories globally.
Testosterone is a small-molecule steroid hormone at only 288 Da. Sandwich immunoassays require simultaneous binding of two antibodies to distinct, non-overlapping epitopes on the same antigen molecule. At 288 Da, testosterone is too small to physically accommodate two IgG antibodies binding simultaneously. Competitive immunoassay is therefore the only viable format for testosterone CLIA and LFA platforms: sample testosterone and labelled testosterone (or testosterone-enzyme/fluorochrome conjugate) compete for a limited pool of antibody binding sites, with signal inversely proportional to sample testosterone concentration.
Sekbio supplies two sheep anti-testosterone monoclonal antibody products: S01-T-1S (Sheep Anti-Human Testosterone mAb, ≥95% purity by SDS-PAGE, PBS pH 7.4, validated for competitive CLIA and LFA) and Testo-W251S (Testosterone antibody, sheep source, lot E06001, competitive immunoassay). Both available from MOQ 1 mg with Certificate of Analysis. Contact info@sekbio.com for datasheets and sample requests.
Sekbio's sheep anti-testosterone monoclonal antibodies (S01-T-1S and Testo-W251S) are characterised for high specificity to testosterone with low cross-reactivity to structurally related androgens including DHEA-S (dehydroepiandrosterone sulfate) and androstenedione. Low cross-reactivity is critical for accurate testosterone quantification in patients with elevated adrenal androgen production (PCOS, CAH, adrenal tumours), where DHEA-S and androstenedione concentrations may be substantially elevated. Lot-specific cross-reactivity data is provided in the Certificate of Analysis.
MOQ is 1 mg for R&D evaluation; OEM supply from 10 mg to gram scale is available. Storage: −20°C long-term; +2°C to +8°C short-term (≤1 month). Formulated in PBS pH 7.4. Avoid repeated freeze/thaw cycles — aliquot before first use if repeated sampling is needed. Shelf life: 3 years from the manufacturing date. Certificate of Analysis provided with every shipment.
Yes. Sekbio supplies testosterone antibodies (S01-T-1S and Testo-W251S) to OEM IVD manufacturers for competitive CLIA and competitive LFA rapid test kit development. ISO 13485-compliant batch data, technical specifications, and regulatory documentation are provided. Sekbio's antibody development and assay platform teams can also provide guidance on competitive assay design, hapten-carrier conjugate selection, and assay optimisation. Contact info@sekbio.com to discuss your testosterone assay development project. Visit our Platforms page for related antibody and assay services.
Request the full technical datasheet, antibody specifications, or discuss OEM supply with our team.