Product Description
The BioDeviceLab COVID-19 S-Protein (S1RBD) Human IgA ELISA Kit is a high-performance enzyme-linked immunosorbent assay developed for the quantitative determination of anti-SARS-CoV-2 S1RBD IgA antibodies in human biological samples. IgA antibodies targeting the Spike protein receptor-binding domain play a critical role in mucosal immunity and early immune defense against SARS-CoV-2 infection.
Measurement of S1RBD-specific IgA responses is widely used to assess mucosal and systemic immunity following natural infection or vaccination, to study immune durability, and to evaluate vaccine-induced antibody responses. This assay combines high analytical sensitivity, excellent specificity for the S1RBD antigen, and robust reproducibility, making it suitable for both conventional laboratory research and advanced biodevice validation workflows.
For Research Use Only (RUO).
Intended Use
This kit is intended for the quantitative determination of human anti-SARS-CoV-2 S1RBD IgA antibodies in:
• Serum
• Plasma
• Saliva
• Cell culture supernatants
Applications include COVID-19 immune response research, vaccine evaluation, mucosal immunity studies, serological assay development, and biodevice calibration and benchmarking.
Assay Principle
This assay employs an indirect sandwich ELISA format:
• Recombinant SARS-CoV-2 S-Protein S1RBD is immobilized on a 96-well microplate.
• Anti-S1RBD IgA antibodies present in the sample bind to the coated antigen.
• A horseradish peroxidase (HRP)-conjugated anti-human IgA detection antibody is added.
• Following substrate (TMB) addition, a colorimetric signal is generated and measured at 450 nm.
• Absorbance is directly proportional to the concentration of anti-S1RBD IgA antibodies in the sample.
Calibration Curve
• A calibration curve is generated using IgA standards or reference calibrators with defined antibody units.
• Mean absorbance values are plotted against antibody concentration on a semi-logarithmic scale.
• A four-parameter logistic (4PL) regression model is recommended for curve fitting.
• Sample concentrations are calculated by interpolation from the standard curve.
Analytical Performance
Dynamic detection range: 1.25 – 100 ng/mL
Limit of detection (LOD): ≤ 0.5 ng/mL
Intra-assay CV: < 10%
Inter-assay CV: < 12%
(Performance aligned with commercial anti-SARS-CoV-2 IgA ELISA kits used in immunology and vaccine research.)
Selectivity & Specificity
The assay demonstrates high specificity for IgA antibodies targeting the SARS-CoV-2 S1RBD with minimal cross-reactivity. Representative specificity profile:
• SARS-CoV-2 S1RBD IgA: 100%
• IgG/IgM isotypes: < 1%
• Antibodies to non-SARS-CoV-2 coronaviruses: minimal cross-reactivity
This specificity ensures accurate assessment of S1RBD-directed IgA immune responses.
Kit Components
Each kit contains sufficient reagents for up to 96 determinations:
• S1RBD antigen-coated 96-well microplate
• IgA standards or reference calibrators
• HRP-conjugated anti-human IgA detection antibody
• Assay buffer
• Wash buffer (10×)
• TMB substrate
• Stop solution
• Detailed assay protocol
Required Materials (Not Provided)
• Microplate reader capable of measuring absorbance at 450 nm
• Adjustable micropipettes and disposable tips
• Plate washer or manual washing equipment
• Plate shaker (recommended)
• Deionized or distilled water
Sample Collection & Handling
• Collect samples using standard laboratory procedures.
• Avoid repeated freeze–thaw cycles.
• Samples with high antibody levels should be diluted using assay buffer.
• Saliva samples should be clarified prior to analysis if necessary.
Quality Control
• Standards and controls should be included in each assay run.
• Duplicate measurements are recommended.
• Acceptance criteria should be defined by the user based on experimental requirements.
BioDeviceLab applies quality-controlled reagent preparation and batch-to-batch consistency practices to support reproducibility and scalability for biodevice development.
Storage & Stability
• Store all components at 2–8 °C.
• Do not freeze reagents unless explicitly stated.
• Unopened kits are stable until the stated expiration date.
• Opened reagents should be handled according to protocol recommendations.
Limitations
• For research use only.
• Not intended for diagnostic or therapeutic procedures.
• Results should be interpreted in the context of study design and immune status.
Applications
• COVID-19 immune response and serology research
• Vaccine immunogenicity and durability studies
• Mucosal and systemic IgA profiling
• Organ-on-chip and immune-on-chip models
• Biodevice calibration and benchmarking
