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SKU: 41A256R

★ 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 S1RBD 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 IgM, 0.12 ml.
  • 10×Standard: Anti-S1RBD antibody (IgM)-50 ul
  • Substrate solution, 12 ml, ready for use.
  • Stop solution, 12 ml, ready for use.

    SARS-CoV-2 S1RBD IgM ELISA Kit is a highly sensitive and specific immunoassay developed by ImmunoDiagnostics for quantitative detection of IgM class antibodies against the S1RBD 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). The distal S1 subunit comprises the receptor-binding domain (RBD) and contributes to stabilization of the prefusion state of the membrane-anchored S2 subunit that contains the fusion machinery. IgM is the first antibody to appear after infection, and the determination of IgM enables confirmation of SARS- CoV-2 infection in patients with symptoms.


    96-well plates are coated with SARS-CoV-2 S1RBD protein that captures antibodies against SARS-CoV-2 S1RBD protein in the sample. After washing away unbound materials, captured IgM against SARS-CoV-2 S1RBD protein is detected by anti-human IgM polyclonal antibodies conjugated with horse radish peroxidase (HRP). After washing step, the chromogenic substrate 3,3’,5,5’-tetramethylbenzidine (TMB) is added. Color reaction is stopped by 2M H2SO4. The amount of IgM class antibodies against SARS-CoV-2 S1RBD 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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