• Anti-SARS-Cov-2 Mpro ELISA Test: the first serological assay designed to detect with high specificity and sensitivity recent and past SARS-CoV-2 infection.

  • This new type of serological test can detect antibodies from the onset of symptoms, allowing to confirm patients with recent and past infection.

  • We are working every day to open opportunities for a better understanding of the immune response and its evolution over time.


Anti-SARS-Cov-2 ELISA kit is a highly sensitive and specific test developed by Immunostep under CSIC patent licence, for the precise detection of either IgG or IgA antibodies against the Mpro (3CLpro) Protein of SARS-Cov-2 virus.

Aids in diagnosis & patient surveillance
Validated by the immunology services of important hospitals and laboratories


Microwell plate

12×8 wells microtiter strip plate coated with recombinant SARS-CoV-2 antigen in vacuum-sealed pouch. 2 microwell sealing foils.

IgG/IgA control solutions

  • 5 ml Positive Control/ Contains CMIT / MIT 3: 1 as a preservative. Ready to use.
  • 5 ml cut-off. Contains CMIT / MIT 3: 1 as a preservative. Ready to use.
  • 5 ml Negative Control. Contains CMIT / MIT 3: 1 as a preservative. Ready to use.


HRP-Conjugated Antihuman Antibody

120 µl of HRP-conjugated anti-human antibody (100X). Contains CMIT / MIT 3: 1 as a preservative.

Wash buffer

50 ml wash buffer (20X). HEPES, NaCl and detergents. Contains Proclin300 as a preservative (<0.0014%).

Stop Solution

12 ml Stop Solution (1X – Ready to use). 0.5M sulfuric acid (H2SO4)

Tetramethylbenzidine (TMB)

12 ml of tetramethylbenzidine (TMB) chromogenic substrate. (1X – Ready to use)

Antibody and Sample Diluent Buffer

25 ml of Antibody and Sample Diluent Buffer (1X – Ready to use). Buffer that minimizes non-specific binding, cross-reactivity and matrix interference, with blue dye. Contains CMIT / MIT 3: 1 as a preservative.

About Mpro Protein

About the Assay


Why Mpro protein is more inmunogenic than other proteins?

Vital Role In Viral Replication

In an attempt to increase the diagnostic possibilities of COVID-19 patients, this assay was developed for the detection of specific antibodies against one of the 16 non-structural proteins, the main viral protease (Mpro or 3CLpro), which plays a critical role in viral replication.

The Mpro protease plays a vital role in processing the polyproteins that are translated from the viral RNA. Although this protein is not exposed in the viral particle, Mpro is elicited after viral infection. Like other b-coronaviruses, SARS-CoV-2 is a positive-sense RNA virus that expresses multiple proteins as a single polypeptide chain, and Mpro cleaves the polyprotein to release mature proteins for the virus. Inhibitors that can block viral replication are promising potential drug candidates that could be used to treat patients suffering from the COVID-19 coronavirus infection.

How do I place an order if I am a laboratory or distributor?

You can place an order via email writing us to order@immunostep.com. Simply choose a kit and send us your order with the reference number stabished in the table.  You can also  contact us in +34 923 29 48 27 (Spain). 

CE/IVD kits are only suitable for clinical use in European Union and countries with EU conformity recognition agreements. Manufactured in Spain by Immunostep under CSIC Patent Licence.

Can I perform this test at home?

These tests are for professional use only. If you are interested in acquiring these kits, please, contact us by  email info@immunostep.com, and we will contact you shortly.

How do I obtein the product if I am a particular?

If you are a particular and you want to acquire this test, please contact us in order to recieve a personalized proposal of distributors near you.

Do you work with a distributor in my country?

Our products are available through our extensive distribution network all over the world. Please contact us and we will give you all the information shortly.

Is the product in stock?

We strive to maintain sufficient inventory to meet your needs. In the rare case that a product is out of stock, you will be notified at the time of your order.