Hepatitis C Virus NS3+NS4+Core Recombinant Antigen for Anti-HCV Serology Rapid Test & CLIA Development
Hepatitis C Virus (HCV) is a single-stranded RNA flavivirus transmitted primarily through blood exposure. Approximately 58 million people globally live with chronic HCV infection — with highest prevalence in Eastern Mediterranean and European regions. Chronic HCV infection leads to progressive liver fibrosis, cirrhosis (15–30% over 20 years), and hepatocellular carcinoma. Despite highly effective direct-acting antiviral (DAA) therapy achieving >95% cure rates, WHO estimates 1 in 5 HCV-infected individuals remains undiagnosed.
HCV diagnosis relies on anti-HCV serology as the first-line screening test. The most immunodominant HCV antigens — used in virtually all commercial anti-HCV IgG/IgM immunoassays — are derived from the NS3 helicase domain, NS4 (NS4a/NS4b), and Core structural protein. These regions generate the earliest and most robust antibody responses in HCV infection, making them the preferred antigen components for both rapid lateral flow serology tests and automated CLIA serology platforms.
Sekbio supplies two complementary HCV recombinant antigens: S05-HCV-101 (optimised for labeled antigen in indirect immunoassays) and S05-HCV-102 (optimised for coated antigen on solid phases). Both are expressed in E. coli with >95% purity, providing reliable immunoreactivity across HCV genotypes 1–6.
Labeled and coated recombinant HCV antigens for complete anti-HCV serology immunoassay development.
| Catalog No. | Product Name | MW | pI | Source | Purity | Application | Storage |
|---|---|---|---|---|---|---|---|
| S05-HCV-101 | Recombinant HCV Antigen (NS3+NS4+Core) | 71.5 kDa | 6.80 | E. coli | >95% | Labeled Antigen — LFA / CLIA / ELISA | −20°C |
| S05-HCV-102 | Recombinant HCV Antigen (NS3+NS4+Core) | 35.3 kDa | 8.25 | E. coli | >95% | Coated Antigen — LFA / CLIA / ELISA | −20°C |
Both antigens supplied in 20 mM PB, 150 mM NaCl, 1‰ P300. May present as clear solution or with small flocculent precipitate — centrifuge before use. MOQ 1 mg. Three-year shelf life. Contact info@sekbio.com for lot availability and technical data.
Both S05-HCV-101 and S05-HCV-102 include epitopes from NS3 helicase, NS4, and Core — the three most immunodominant HCV antigen regions. Multi-region fusion improves seroassay sensitivity in early acute infection (Core antibodies appear first), chronic infection (NS3/NS4 predominate), and across all six HCV genotypes.
S05-HCV-101 (71.5 kDa, pI 6.80) for labeled antigen and S05-HCV-102 (35.3 kDa, pI 8.25) for coated antigen have distinct molecular weights and isoelectric points, optimised for their respective roles. Using both maximises epitope coverage and assay sensitivity across different antibody epitope specificities in the patient population.
E. coli expression with >95% purity ensures high antigen-specific immunoreactivity and minimises non-specific background in LFA rapid tests and CLIA assays. High purity reduces false-positive rates from E. coli host protein antibodies — a known cross-reactivity issue with lower-purity recombinant antigens.
The NS3+NS4+Core fusion protein design provides broad coverage across HCV genotypes 1–6, supporting development of WHO-recommended pan-genotypic screening assays. Genotype-specific prevalence varies by geography: genotype 1 dominates in North America and Europe; genotypes 3 and 4 are prevalent in South/Southeast Asia and Egypt, respectively.
E. coli expression provides cost-effective, highly scalable antigen production for OEM manufacturers requiring gram-scale quantities. Unlike mammalian expression, E. coli production avoids adventitious agent risks from animal-derived components, simplifying biosafety documentation for regulatory submissions.
ISO 13485-compliant manufacturing. 3-year shelf life at −20°C. MOQ 1 mg for R&D; gram-scale OEM supply available. CoA with lot-specific purity, concentration, and reactivity data. Supports CE IVD, NMPA, WHO prequalification, and FDA submissions for anti-HCV diagnostic kit manufacturers.
Anti-HCV lateral flow assay rapid tests are the primary screening tool for HCV in low- and middle-income countries (LMICs), health fairs, and community screening programs. Using S05-HCV-102 (coated antigen) on nitrocellulose membrane test line and S05-HCV-101 (labeled antigen) conjugated to colloidal gold as the detection system, indirect LFA format detects anti-HCV IgG/IgM in whole blood, serum, or plasma with WHO-recommended sensitivity >98% and specificity >99%.
Third-generation anti-HCV ELISAs and CLIAs use recombinant HCV antigen coated on wells/beads (S05-HCV-102) to capture anti-HCV antibodies, followed by labeled antigen detection (S05-HCV-101) in a double-antigen sandwich format — offering superior sensitivity over second-generation single-antigen assays. This format also detects both IgM and IgG simultaneously, with sensitivity >99.5% in chronic HCV infection.
WHO's global HCV elimination strategy targets screening 80% of infected individuals and treating 80% by 2030. Africa, South/Southeast Asia, and Middle East are the primary high-prevalence regions where affordable anti-HCV rapid tests are essential. Sekbio's E. coli-expressed HCV antigens — cost-effective at scale, 3-year shelf life at −20°C — support OEM manufacturers developing affordable HCV rapid tests for WHO prequalified and NMPA-registered kits targeting these markets.