Quantum Blue® SARS-CoV-2 RBD+

The Quantum Blue® SARS-CoV-2 RBD+ is a special in vitro diagnostic, rapid lateral flow assay for the qualitative determination of antibodies against the Receptor Binding Domain (RBD) antigen of SARS-CoV-2 in human serum and capillary blood. The Quantum Blue® SARS-CoV-2 RBD+ is intended as an aid in identifying individuals with an adaptive immune response to SARS-CoV-2. The test is designed for health professionals working in a laboratory or point-of-care setting and qualitatively detects IgM, IgA and IgG antibodies specific to SARS-CoV-2.

The challenge for antibody testings in the current COVID-19 pandemic is to specifically identify patients who developed neutralizing antibodies against this virus. This is even more important in regard to the unprecedent largest global vaccination campaign against SARS-CoV-2. The spike protein and more specifically its RBD is the main target of vaccines for COVID-19. We decided to put a particular effort into the development of an antibody test based on our proprietary Quantum Blue® technology for lateral flow tests, with exceptional properties:

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Special Test Characteristics

The key target for neutralizing antibodies is the RBD of the spike protein. RBD is well known to be responsible for the interaction with human cells. Antibodies against RBD have the unique potential to disrupt the entry gate to human cells. For this reason, RBD is the antigen of choice of many vaccines which are in the final development process or are already approved. That is why we focused on RBD to develop the Quantum Blue® antibody test for neutralizing antibodies against SARS-CoV-2.

We designed a unique and extended RBD construct for our double antigen “sandwich” method: the antigen is added to the test line as well as conjugated to nanobeads to capture and visualize anti SARS-CoV-2 antibodies present in patient samples. RBD specific binders are added to the control line to capture the nanobeads for proving the functionality of the test. This special design allows to capture SARS-CoV-2 neutralizing antibodies of all isotypes, IgM, IgG and IgA with high specificity.


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Test Procedure

The Quantum Blue® SARS-CoV-2 antibody test is based on the use of finger prick blood or serum and the qualitative test result can be immediately interpreted by eye. For verification and documentation of the test result, the test cassette can also be analysed with the BÜHLMANN Quantum Blue® Readers.
Testing has never been so quick and easy:

Clinical Agreement

The ability of the BÜHLMANN Quantum Blue® SARS-CoV-2 RBD+ to detect an adaptive immune response to previous infection with SARS-CoV-2 was evaluated using clinical serum samples collected from one hundred and forty-three (143) patients. Fifty-seven (57) positive control patients with a previous positive RT-PCR test for SARS-CoV-2 infection and eighty-six (86) negative control patients with blood samples collected before December 2019 and tested positive for IgG antibodies against at least one other respiratory pathogen were included in the study. Currently the assay is being evaluated externally. The Evaluation includes samples that have been tested for neutralizing properties, where results are soon expected to be even more stringent for neutralizing antibodies.

Quantum Blue® SARS-CoV-2 RBD+ Product Information

Test Quantum Blue® SARS-CoV-2 RBD+
Order Code LF-COV2-25
Time to Result 15 min (approx.)
Sample Type Serum or capillary blood
Assay Type Lateral Flow Assay
Readout Eye or Quantum Blue® Reader
Reader Compatibility Quantum Blue® Reader 3rd generation /
Quantum Blue® Reader 2nd generation /

Quantum Blue® SARS-CoV-2 RBD+ was discotinued