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SKU: 41A247R

★ Download Datasheet PDF ★





Each kit is sufficient for 96 tests and contains the following components:


  • One aluminum pouch with a Microwell plate (12 strips of 8 wells each) coated with SARS-CoV-2 S1 protein, sealed. The microwell strips can be used separately.
  • 10×Wash buffer, 40 ml.
  • 5×Assay buffer, 20 ml.
  • 100×Detection antibody solution: HRP-conjugated anti-human IgA monoclonal antibody, 0.12 ml.
  • 10×Standard: Anti-S1 antibody (IgA)-50 ul
  • Substrate solution, 12 ml, ready for use.
  • Stop solution, 12 ml, ready for use.

    SARS-CoV-2 S1 IgA ELISA Kit is a highly sensitive and specific immunoassay developed by ImmunoDiagnostics for quantitative detection of IgA class antibodies against the S1 of SARS-CoV-2 in human blood.

    This product is intended for research use only.


    SARS-CoV-2 is an enveloped virus with a positive-sense RNA genome and a nucleocapsid of helical symmetry. The SARS-CoV-2 entry into host cells is mediated by the transmembrane spike (S) glycoprotein, which is the main target of neutralizing antibodies upon infection and the focus of the therapeutic and vaccine design. S comprises two functional subunits responsible for binding to the host cell receptor (S1 subunit) and fusion of the viral and cellular membranes (S2 subunit). Immunoglobulin A (IgA) plays a crucial role in the immune function of mucous membranes. In the blood, IgA interacts with Fc receptor to initiate inflammatory responses.


    96-well plates are coated with SARS-CoV-2 S1 protein that captures antibodies against SARS-CoV-2 S1 protein in the sample. After washing away unbound materials, captured IgA against SARS-CoV-2 S1 protein is detected by anti-human IgA monoclonal antibodies conjugated with horse radish peroxidase (HRP), which is specific to human IgA, with no cross-reaction with human IgG or IgM. After washing step, the chromogenic substrate 3,3’,5,5’-tetramethylbenzidine (TMB) is added. Color reaction is stopped by 2M H2SO4. The amount of IgA class antibodies against SARS-CoV-2 S1 captured inside the wells is proportional to the color density generated in the coupled oxidation-reduction reaction.


    Handle serum or plasma sample in accordance with National Committee for Clinical Laboratory Standards guidelines for preventing transmission of blood-borne infection.

    • Do not use grossly hemolyzed or lipemic samples.
    • Human Serum: Use a blood separator tube and allow sample to clot for 30 minutes, then centrifuge for 10 minutes at 1000g. When the human serum is tested, it should be diluted 100-fold at least.
    • Human plasma: Treat blood with anticoagulant such as citrate, EDTA or heparin.  Centrifuge for 10 minutes at 1000g within 30 minutes for plasma collection. When the human plasma is tested, it should be diluted 100-fold at least.
    • Samples cannot be tested immediately should be aliquoted and must be stored frozen below -20°C. Avoid repeated freeze-thaw cycle.
    • Perform preliminary experiment to determine the optimum detection sample dilution.

    • The kit should be stored at 2-8°C, and all reagents should be equilibrated to room temperature before use. Immediately after use remaining reagents should be returned to cold storage (2-8°C).
    • Expiry of the kit and reagents is stand on labels. 
    • Once opened, the strips may be stored at 2-8°C for up to one month.

The currency used on this website is United States Dollars (USD). All prices are displayed and transactions are processed in USD. For orders outside Hong Kong or if you would like to have other currencies available, please contact us for a quote.

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