Cytokeratin-19 Fragment Monoclonal Antibody for Non-Small Cell Lung Cancer CLIA Immunoassay Development
CYFRA21-1 (Cytokeratin Fragment 21-1) is a soluble fragment of cytokeratin 19 (CK19), an intermediate filament protein constitutively expressed in epithelial tissues. During malignant transformation and neoplastic cell death, CK19 fragments are released into circulation. Serum CYFRA21-1 is significantly elevated in non-small cell lung cancer (NSCLC) — particularly squamous cell carcinoma (~70% sensitivity) and adenocarcinoma (~50% sensitivity) — with a normal reference range typically <3.3 ng/mL.
CYFRA21-1 is the most sensitive single serum marker for NSCLC among cytokeratin fragments, outperforming CEA in squamous cell carcinoma. It is used clinically for NSCLC diagnosis support, staging, treatment monitoring, and recurrence detection. Elevated CYFRA21-1 (>3.3 ng/mL) at baseline correlates with advanced stage disease (III–IV) and poorer prognosis in NSCLC patients.
For IVD CLIA assay development, CYFRA21-1 requires a matched antibody pair recognising non-overlapping epitopes. Sekbio offers a unique panel including both a recombinant human IgG and mouse IgG1 antibodies, enabling anti-interference design strategies for clinical CLIA platforms.
Recombinant human IgG and Mouse IgG1 antibodies for flexible pairing in CLIA CYFRA21-1 immunoassay development.
| Catalog No. | Product Name | Isotype | Concentration | Purity | Intended Use | Storage |
|---|---|---|---|---|---|---|
| C211-119-2H | Recombinant Human Anti-CYFRA21-1 mAb | Human IgG | 5.78 mg/mL | >90% SEC-HPLC | Capture or Detection — CLIA | +2°C to +8°C |
| C211-119-2M | Mouse Anti-CYFRA21-1 mAb | Mouse IgG1 | 4.21 mg/mL | >90% SEC-HPLC | Capture or Detection — CLIA | +2°C to +8°C |
| C211-119-3M | Mouse Anti-CYFRA21-1 mAb | Mouse IgG1 | 4.41 mg/mL | >90% SEC-HPLC | Capture or Detection — CLIA | +2°C to +8°C |
All supplied in 20 mM PB, 150 mM NaCl, pH 7.4. MOQ 1 mg. Recommended pairing: C211-119-2H (detection) + C211-119-2M or C211-119-3M (capture). Contact info@sekbio.com for epitope mapping and pairing recommendations.
Unique recombinant human IgG plus mouse mAb options for flexible, interference-resistant CYFRA21-1 assay design.
C211-119-2H is a recombinant human anti-CYFRA21-1 IgG — rare in commercial CYFRA21-1 antibody offerings. Human IgG format minimises HAMA (human anti-mouse antibody) interference, reduces false-positive risk from RF (rheumatoid factor), and provides consistent lot-to-lot expression from CHO cell lines.
Using C211-119-2H (human IgG, detection) + C211-119-2M or 3M (Mouse IgG1, capture) creates a multi-species sandwich that significantly reduces heterophilic antibody interference — a known challenge in CYFRA21-1 CLIA assays. This design mirrors the anti-interference approach used in leading commercial CYFRA21-1 assays.
Two distinct mouse IgG1 clones (C211-119-2M, C211-119-3M) targeting different CK19 epitopes allow flexible pairing with the human IgG antibody. Developers can screen both to select the combination delivering optimal sensitivity, specificity, and signal-to-noise ratio for their specific CLIA platform.
All three CYFRA21-1 antibodies are affinity-purified from cell culture supernatants with >90% purity by SEC-HPLC and <5% aggregation. High purity reduces background signal in CLIA platforms and ensures reproducible antibody coating on magnetic beads or microparticles.
All CYFRA21-1 antibodies are stable at +2°C to +8°C without requiring −20°C deep freeze storage, simplifying supply chain management for OEM manufacturers and reducing cold chain logistics costs during international shipment.
Sekbio supplies antibody pairs for all major lung cancer markers (CYFRA21-1, CEA, NSE, ProGRP, SCC) from a single ISO 13485-certified source, enabling OEM manufacturers to streamline reagent procurement for multi-analyte lung cancer CLIA panels.
CYFRA21-1 >3.3 ng/mL supports NSCLC diagnosis in combination with imaging. Sensitivity is highest in squamous cell carcinoma (~70%) and adenocarcinoma (~50%). At a cut-off of 3.3 ng/mL, specificity for NSCLC vs. benign lung disease approaches 90%. Sekbio's antibody pair enables the high-sensitivity CLIA assay required for reliable <1 ng/mL baseline measurement and elevated-range quantification.
Serial CYFRA21-1 measurement during chemotherapy, targeted therapy (EGFR inhibitors), and immunotherapy monitors treatment response. A progressive CYFRA21-1 rise during or after treatment predicts disease progression before radiological evidence. CYFRA21-1 is one of the most sensitive post-treatment recurrence markers for NSCLC, particularly squamous cell histology.
CYFRA21-1 is routinely combined with CEA (adenocarcinoma), NSE (SCLC), ProGRP (SCLC), and SCC antigen (squamous cell) on automated CLIA analyzers. Sekbio supplies all five lung cancer marker antibody pairs from a single ISO 13485-certified source. Multi-marker panel algorithms improve sensitivity for NSCLC diagnosis to ~80% while maintaining >90% specificity.
CYFRA21-1 reagents are among the highest-volume oncology marker tests on automated CLIA platforms globally. OEM analyzer manufacturers in China, Europe, and Korea can integrate Sekbio's CYFRA21-1 antibody pair — with recombinant human IgG detection antibody for interference reduction — into CLIA reagent kits. ISO 13485 batch data supports NMPA, CE IVD, and FDA submissions.
CYFRA21-1 is a soluble fragment of cytokeratin 19 (CK19) released into serum during malignant epithelial cell degradation. Normal serum CYFRA21-1 is <3.3 ng/mL. CYFRA21-1 is the most sensitive serum marker for NSCLC squamous cell carcinoma (~70% sensitivity) and is used for NSCLC diagnosis support, staging, treatment monitoring, and recurrence detection in combination with CEA, NSE, and ProGRP.
C211-119-2H (Recombinant human IgG, 5.78 mg/mL, >90% SEC-HPLC, +2–8°C), C211-119-2M (Mouse IgG1, 4.21 mg/mL, >90% SEC-HPLC, +2–8°C), and C211-119-3M (Mouse IgG1, 4.41 mg/mL, >90% SEC-HPLC, +2–8°C). All MOQ 1 mg.
C211-119-2H (human IgG) minimises HAMA (human anti-mouse antibody) and rheumatoid factor interference that causes false-positive results in mouse mAb-only CLIA sandwich assays. A multi-species pairing (human IgG detection + mouse mAb capture) significantly reduces such interference — a key quality advantage for clinical CLIA platforms.
Validated for CLIA (chemiluminescence immunoassay) sandwich format. Contact info@sekbio.com for CLIA platform-specific pairing recommendations, working concentrations, and expected signal-to-noise ratios.
Yes. Sekbio supplies antibody pairs for CYFRA21-1, CEA, NSE, ProGRP, and SCC — all major lung cancer CLIA markers — from a single ISO 13485-certified source. Contact info@sekbio.com for multi-marker panel procurement or visit Products.
All three CYFRA21-1 antibodies (C211-119-2H, C211-119-2M, C211-119-3M) are stable at +2°C to +8°C — no −20°C freeze required. Avoid multiple freeze/thaw cycles. Shelf life: 3 years from manufacturing date. Contact info@sekbio.com for lot-specific expiry dates.
Request antibody pairing data, technical datasheet, or discuss OEM supply with our team.