Uniquely measuring antibodies reactive to both RBD and NP

Uniquely measuring antibodies reactive to both RBD and NP

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    Simultaneous detection of IgG antibodies to RBD & NP maximises assay sensitivity reducing false negatives
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    Confirmation of an adaptative immune response to SARS-CoV-2
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    Distinguish vaccinated from naturally infected individuals
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    Specificity of 99.5% and sensitivity of 100% ≥ 10 days post SARS-CoV-2 PCR confirmation
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    Identify incidence of SARS-CoV-2 infection in vaccinated individuals
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    Qualitative and semi-quantitative results provided

The Randox CE marked SARS-CoV-2 IgG (RBD & NP) array utilises patented biochip technology to simultaneously detect IgG antibodies against both leading COVID-19 diagnostic antigens; Spike Receptor Binding Domain (RBD) and Nucleocapsid protein (NP). The SARS-CoV-2 IgG (RBD & NP) array is compatible with both capillary and venous blood collection. 

Maximum sensitivity is ensured through detection of antibodies against both proteins making the assay superior compared to other commercially available serology tests where false negative results may occur.  Measurement of both RBD and NP IgG antibodies also provides an opportunity to discriminate vaccinated versus naturally infected individuals. Spike is one of the major vaccine targets against SARS-CoV-2 with antibodies against Spike RBD correlating well with protection while Nucleocapsid is an immunodominant protein expressed with high immunogenicity during the early stages of SARS-CoV-2 infection.

Highly sensitive and specific serological assays are crucial for surveillance, to help uncover the burden of disease and to get accurate estimates of morbidity and mortality associated with SARS-CoV-2. Serological assays are also required to evaluate immunological response at an individual/population level and during vaccine trials.

Crucially, simultaneous measurement of antibodies to RBD and NP provides a tool to monitor breakthrough SARS-CoV-2 infection in vaccinated individuals. This testing approach has wider societal implications in the context of measuring ongoing vaccine effectiveness against evolving SARS-CoV-2 variants such as the Delta variant.

SARS-CoV-2 IgG (RBD & NP) Array

  • RBD
  • NP

The S protein consisting of S1 and S2 subunits is located on the surface of the SARS-CoV-2 virus making it highly immunogenic.  The S protein plays an important role in viral attachment, fusion and entry to the host cell, as such it serves as a target for the development of antibodies, entry inhibitors and vaccines. The Receptor Binding Domain (RBD) located on the S1 subunit is the key target for neutralising antibodies. Unlike N protein, RBD is associated with less cross reactivity with other coronaviruses and is therefore highly specific to SARS-CoV-2.

The nucleocapsid protein (NP) is abundantly expressed in individuals infected with SARS-CoV-2 and is highly immunogenic. N protein is normally very conserved, because of this homology recent research cautions against the use of serology tests that detect antibodies against the N protein alone.

Ordering Information

DescriptionCat Code
SARS-CoV-2 IgG (RBD & NP) ArrayEV4447
SARS-CoV-2 IgG (RBD & NP) Array Control KitEV4448

Available Platforms

Evidence Investigator

Cost effective and efficient semi-automated multiplex testing solution

Medium to high throughput (54 samples in 1.5 hours)

Limited sample volume requirement (10ul)

Comprehensive immunoassay and molecular test menu available

Evidence Investigator


Fully automated batch immunoanalyser for
faster testing & accurate results

High throughput (2070 samples per day)

Limited sample volume requirement (10ul)

Comprehensive immunoassay test menu available

Want to know more?

Contact us or visit our COVID-19 Monitoring & Management page

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