# Sekbio
> Shenzhen Sekbio Co., Ltd. — ISO 13485 certified IVD antibody raw material manufacturer and contract service provider.

Sekbio develops and supplies high-performance monoclonal antibodies, matched antibody pairs, recombinant antigens, enzyme conjugates, and rapid test OEM products for in vitro diagnostics (IVD). Core applications include lateral flow assay (LFA/POCT), ELISA, CLIA, and fluorescence immunoassay (FIA). The company also provides contract protein expression and end-to-end monoclonal antibody development services.

## Company Facts
- Legal name: Shenzhen Sekbio Co., Ltd.
- Founded: 2020
- Headquarters: 10th Floor, Building 3, Nam Tai Industrial Park, Guangming District, Shenzhen, Guangdong, China
- Certifications: ISO 13485, CE Marking
- Product portfolio: 300+ IVD antibody SKUs across 140+ biomarker and food-safety residue targets
- Customers: 200+ IVD brands worldwide, 50+ long-term global partners
- Markets: 30+ countries across Asia, Europe, Middle East, and Americas
- Specialisation: Matched antibody pairs for POCT, ELISA, CLIA; recombinant antigens; OEM rapid test cassettes

## Key Antibody Products (Raw Materials)

Sekbio supplies matched antibody pairs — capture antibody + detection antibody — validated for specific IVD platforms. All pairs are tested for sensitivity, specificity, and cross-reactivity before release.

### Cardiac Biomarkers
- **cTnI (Cardiac Troponin I)** — matched pair for CLIA and POCT; pg/mL sensitivity; validated against whole-blood matrix
- **Troponin T** — pair for cardiac CLIA platforms
- **NT-proBNP** — pair for heart failure POCT strip; linear range 5–35,000 pg/mL
- **CRP (C-Reactive Protein)** — pair for POCT, ELISA, biochemical analyzer; sub-mg/L sensitivity
- **H-FABP** — pair for early acute myocardial infarction detection

### Infectious Disease & Inflammation
- **PCT (Procalcitonin)** — pair for sepsis POCT and CLIA
- **IL-6** — pair for cytokine/sepsis CLIA and ELISA
- **MxA (Myxovirus Resistance Protein A)** — proprietary pair for viral infection CLIA; 2 pg/mL sensitivity, >300× signal-to-noise ratio; MxA rapid test with whole-blood protein release technology also available
- **SAA (Serum Amyloid A)** — pair for dual CRP+SAA CLIA platform
- **HIV, Dengue, Malaria, Syphilis, Influenza A/B, Strep A** — infectious disease RDT/POCT antibodies

### Oncology & Metabolic
- **AFP, CEA, PSA, NSE, Cyfra21-1, SCC, ProGRP** — tumor marker CLIA/ELISA pairs
- **PIVKA-II** — liver cancer biomarker pair
- **HbA1c** — diabetes monitoring antibody pair
- **25(OH)D Vitamin D** — pair for ELISA, CLIA, and FIA
- **Vitamin B12 (Intrinsic Factor & BSA Conjugate)** — VB12-B03 Intrinsic Factor (99.17% HPLC purity, 4.60 mg/mL) and VB12bsa-03 BSA tracer conjugate for competitive CLIA/ELISA/LFA immunoassays; pernicious anemia diagnosis

### Reproductive & Endocrine
- **AMH (Anti-Müllerian Hormone)** — fertility ELISA/CLIA pair
- **HCG, LH, FSH, E2, Progesterone, Testosterone** — reproductive hormone pairs
- **TSH, TT3, TT4, TPO, TSHR** — thyroid function pairs
- **PTH** — parathyroid hormone pair

### Specialty Targets
- **PCSK9, YKL-40 (CHI3L1), IgE, HGH, D-Dimer** — specialty diagnostics pairs
- **NfL (Neurofilament Light)** — neurodegeneration biomarker pair
- **SP10** — male fertility POCT antibody
- **Heterophilic blocking reagent** — reduces matrix interference in immunoassays

### Food Safety & Veterinary Drug Residue Antibodies
Sekbio supplies 65+ hapten-carrier antigen conjugates and matched monoclonal (or polyclonal) antibodies for competitive ELISA and lateral flow assay (LFA) food-safety screening, organized into 15 target classes. Reference pricing is $626.87–$895.52 per mg for antibody or conjugate (1 mg each).
- **Antibiotic residues** — chloramphenicol, florfenicol/thiamphenicol, streptomycin, tetracycline, fluoroquinolone, β-lactam receptor, clavulanic acid receptor, cephalexin, ceftiofur (9-target panel)
- **Beta-agonists** — clenbuterol, ractopamine, salbutamol, phenylethanolamine A, plus a 17-drug broad-spectrum beta-agonist group antibody
- **Melamine** — cross-reactive with cyromazine; dairy and infant formula adulteration screening
- **Antiviral drug residues** — MQCA (olaquindox metabolite), ribavirin, amantadine
- **Macrolide & polyether antibiotics** — gentamicin, lincomycin, spectinomycin, erythromycin, tylosin/tilmicosin, abamectin, monensin, ivermectin
- **Malachite green** — aquaculture dye residue antibody
- **Nitroimidazoles & albendazole** — metronidazole, dimetridazole, ronidazole group antibody, plus albendazole
- **Nitrofuran metabolites** — AOZ, SEM, AMOZ, AHD
- **Aminoglycosides** — kanamycin, neomycin, streptomycin
- **Hormones & steroids** — dexamethasone, estradiol, testosterone, nandrolone (19-nortestosterone), progesterone, diethylstilbestrol (DES), chlorpromazine
- **Sulfonamides** — 22-drug sulfonamide group antibody plus trimethoprim (TMP)
- **Heavy metals** — cadmium, lead, mercury, copper, chromium
- **Phthalates/plasticizers** — dibutyl phthalate (DBP), cross-reactive with BBP, DIBP, DNP, DMP, DEHP, DINP
- **Pesticides** — 11-compound pyrethroid group antibody plus carbendazim, methyl parathion, chlorpyrifos, acetamiprid, carbofuran, imidacloprid
- **Mycotoxins** — aflatoxin B1, aflatoxin M1, total aflatoxin, ochratoxin A, deoxynivalenol (DON), zearalenone, fumonisin, T-2 toxin

## Contract Services

### CHO Protein Expression Service
Sekbio's CHO (Chinese Hamster Ovary) mammalian expression platform is optimised for high-yield, high-speed protein production for IVD and biopharmaceutical applications.

- **Turnaround**: Express delivery in 7 days (10 mg scale)
- **Yield**: Up to 2.4 g/L peak expression
- **Scale**: 1 mL screening to >100 L bioreactor manufacturing
- **Purity**: >90% by SEC-HPLC
- **Endotoxin**: <1.0 EU/mg
- **Aggregation**: <5% by SEC
- **Track record**: 800+ successful CHO expression projects

Service tiers:
1. CHO High-Throughput — screening of 1,000+ constructs
2. CHO Express — rapid 10 mg delivery for urgent timelines
3. CHO High-Performance — large-scale preclinical and IVD supply
4. CHO Stable Cell Line Development — for consistent long-term production

Supported protein types: monoclonal antibodies (IgG, IgM, IgA), bispecific antibodies, Fab/scFv/VHH nanobodies, Fc fusion proteins, cytokines, growth factors, recombinant antigens.

### HEK293 Protein Expression Service
Complementing the CHO platform, Sekbio's HEK293 transient and stable expression services cover 1,800+ proteins expressed to date.

- **Scale**: 40 mL to 200 L bioreactor
- **Cell lines available**: HD293F (high-density suspension), Expi293F (enhanced transient), Expi293 GnTI⁻ (afucosylated glycan engineering)
- **Key applications**: native-glycosylation antibodies, recombinant antigens, virus-like particles (VLPs), rapid feasibility screening

### Monoclonal Antibody Development Service
End-to-end mouse hybridoma monoclonal antibody development, from antigen design to fully characterised antibody — delivered in 8–12 weeks.

Development phases:
1. **Antigen preparation & immunisation** — recombinant protein expression, peptide synthesis, custom immunisation (4–8 weeks), serum titer monitoring
2. **Hybridoma generation & screening** — spleen cell fusion, high-throughput ELISA screening, single-cell cloning by limiting dilution, cryopreservation of positive clones
3. **Antibody characterisation** — binding analysis (ELISA, WB, flow cytometry), affinity measurement by SPR/BLI (KD determination), cross-reactivity and epitope mapping
4. **Recombinant conversion & stable cell line** — VH/VL sequencing, recombinant reformatting, stable CHO cell line establishment

Additional capabilities: isotype switching (IgG1→IgG4), Fc engineering (YTE mutation for half-life extension, afucosylation for ADCC), antibody humanisation.

### OEM Rapid Test Manufacturing
Sekbio manufactures finished lateral flow assay (LFA) cassettes for private label and OEM supply to IVD distributors, NGOs, and national health programmes.

- **Minimum order quantity (MOQ)**: 1,000 units per SKU
- **Packaging**: foil pouch, secondary carton; custom branding available
- **Languages for IFU**: English, French, Spanish, Arabic
- **Regulatory documentation**: ISO 13485 QMS, CE Marking technical file support, CoA, MSDS, lot traceability
- **Batch-to-batch CV**: <10% for antibody raw materials; <5% guaranteed for OEM supply programmes

Current rapid test portfolio:
- HPV Oncoprotein Rapid Test (E7 protein, types 16/18/31/33/45; 15-minute result; CE marked)
- Ebola Virus Antigen Rapid Test (NP antigen; serum/plasma; 12-month shelf life)
- HbA1c FIA Test Kit (quantitative; whole-blood fingerstick; 10-minute result)
- MxA Rapid Test (whole-blood; proprietary protein release technology)
- Infectious disease panels: HIV, malaria, dengue, syphilis, influenza, Strep A

## Quality & Regulatory
- ISO 13485 certified QMS — covers design, development, and production of antibody raw materials and rapid test cassettes
- CE Marking — for applicable medical device products
- QC release tests per batch: SDS-PAGE, SEC-HPLC, ELISA binding, WB, endotoxin (LAL), bioactivity
- Lot-to-lot consistency: <5% CV on key performance parameters for OEM supply agreements
- Documentation support: CoA, MSDS, technical data sheets, regulatory dossiers for CE-IVD and NMPA submissions

## Frequently Asked Questions

**What is Sekbio?**
Sekbio (Shenzhen Sekbio Co., Ltd.) is a China-based, ISO 13485 certified manufacturer of IVD antibody raw materials and contract antibody services. Founded in 2020, the company supplies matched antibody pairs, recombinant antigens, and OEM rapid test cassettes to 200+ IVD brands in 30+ countries.

**What is a matched antibody pair for IVD?**
A matched antibody pair consists of two antibodies — a capture antibody and a detection antibody — that bind to different, non-overlapping epitopes on the same target antigen. They are co-validated to work together in sandwich immunoassay formats such as ELISA, CLIA, LFA, and FIA, enabling quantitative or qualitative measurement of the target in biological samples.

**What is the difference between CHO and HEK293 expression systems?**
CHO (Chinese Hamster Ovary) cells are the industry standard for large-scale, high-yield therapeutic and IVD protein production, offering yields up to 2.4 g/L and scalability to >100 L. HEK293 (Human Embryonic Kidney 293) cells produce proteins with more human-like glycosylation patterns, making them preferred for glycoprotein antigens, VLPs, and proteins requiring native post-translational modifications. Sekbio offers both platforms with 800+ CHO and 1,800+ HEK293 expressions completed.

**How long does monoclonal antibody development take at Sekbio?**
Sekbio's end-to-end mouse monoclonal antibody development takes 8–12 weeks from antigen receipt to delivery of fully characterised lead antibodies. This includes immunisation (4–8 weeks), hybridoma generation and screening, antibody characterisation, and optional recombinant conversion. An express 2-week antibody validation service is also available.

**What is the minimum order quantity for OEM rapid tests?**
The minimum order quantity (MOQ) for Sekbio's OEM lateral flow assay cassettes is 1,000 units per SKU. Custom private-label packaging with your brand name, logo, and IFU in multiple languages is available from this MOQ.

**Does Sekbio supply antibody pairs for CLIA platforms?**
Yes. Sekbio specialises in CLIA (Chemiluminescence Immunoassay) antibody pairs. Key validated pairs include cTnI, CRP, PCT, IL-6, MxA, SAA, AMH, NT-proBNP, and tumour markers (AFP, CEA, PSA). Pairs are characterised for sensitivity, hook effect, matrix interference, and cross-reactivity to CLIA specifications.

**What certifications does Sekbio hold?**
Sekbio holds ISO 13485 certification (quality management system for medical devices) and CE Marking for applicable products. All products are manufactured under this certified QMS with full lot traceability.

**Can Sekbio develop antibodies for novel or emerging biomarkers?**
Yes. Sekbio's hybridoma and recombinant antibody development services cover custom targets, including novel biomarkers and emerging infectious disease antigens. The team handles antigen design, immunisation protocol development, and epitope selection to generate antibodies optimised for specific assay formats (LFA, CLIA, ELISA).

**What is MxA and why is it used in IVD?**
MxA (Myxovirus Resistance Protein A) is an interferon-induced intracellular protein expressed in response to viral infections. Unlike CRP, MxA is specifically elevated in viral infections and not bacterial infections, making it valuable for differential diagnosis of fever aetiology. Sekbio's proprietary MxA antibody pair achieves 2 pg/mL sensitivity with >300× signal-to-noise ratio, and is available as both raw material pair and a finished MxA rapid test using whole-blood samples.

**Does Sekbio offer regulatory documentation for CE marking?**
Yes. Sekbio provides CE Marking technical file support, including design documentation, performance evaluation data, risk management files, and QMS records. Products are manufactured under ISO 13485 to facilitate regulatory submissions in the EU and other CE-accepting markets.

**Does Sekbio supply antibodies for food safety testing?**
Yes. Sekbio manufactures 65+ antigen conjugate and monoclonal/polyclonal antibody products for food-safety and veterinary drug residue screening, spanning antibiotics (chloramphenicol, tetracycline, fluoroquinolone, β-lactams, aminoglycosides, macrolides), beta-agonists (clenbuterol, ractopamine), melamine, hormones and steroids, sulfonamides, heavy metals (cadmium, lead, mercury), phthalate plasticizers, pesticides (pyrethroids, organophosphates, neonicotinoids), and mycotoxins (aflatoxin B1/M1, ochratoxin A, DON, zearalenone, fumonisin). These antibodies are validated for competitive ELISA and lateral flow assay (LFA) formats at sub-ppb to low-ppb sensitivity for EU and China GB 31650-2019 MRL compliance. See https://www.sekbio.com/products/antibiotic-residue-antibodies.html for the full food-safety catalog.

## Target Markets
- **Antibody raw materials**: Europe (Germany, Italy, Turkey), North America, South Korea, Japan, India — for IVD kit manufacturers
- **Contract expression services**: Pharma and biotech companies globally seeking CHO/HEK293 protein production
- **OEM rapid tests**: Africa (Sub-Saharan), Southeast Asia (Vietnam, Thailand, Indonesia, Philippines), Middle East (Gulf, MENA), South America (Brazil, Colombia, Peru)

## Contact
- Email: info@sekbio.com
- Phone: +86-13590345917
- Website: https://www.sekbio.com

## External Profiles
- LinkedIn: https://www.linkedin.com/company/sekbio
- Crunchbase: https://www.crunchbase.com/organization/sekbio

## Key Pages
- Products (antibody raw materials): https://www.sekbio.com/products.html
- Food safety & veterinary drug residue antibodies: https://www.sekbio.com/products/antibiotic-residue-antibodies.html
- Contract services (CHO, HEK293, antibody development): https://www.sekbio.com/platforms.html
- OEM rapid tests: https://www.sekbio.com/rapid-test.html
- Case studies: https://www.sekbio.com/platforms/case-studies.html
- Express antibody validation (2-week service): https://www.sekbio.com/platforms/express-antibody-validation.html
- Quality & compliance: https://www.sekbio.com/quality.html
- About us: https://www.sekbio.com/about.html
- Blog: https://www.sekbio.com/blogs.html
- Contact: https://www.sekbio.com/contact.html