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C19RBDHC30M: SPR sensor chip for COVID-19 research

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SARS-CoV-2 virus
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Because of its central role in the viral infection mechanism, the Receptor Binding Domain (RBD) of SARS-CoV-2 Spike Protein is a major focus of COVID-19-related therapeutics, vaccine and diagnostics development.

Surface Plasmon Resonance (SPR) biosensors are valuable tools for research and diagnostics, as they provide an unmatched information depth on various biomolecular interactions with immobilized binders (ligands).

To meet the rapidly increasing demand for COVID-19-related research tools, XanTec presents the first cross-platform, ready-to-use COVID-19 SPR sensor chip. It consists of SARS-CoV-2 RBD protein homogenously preimmobilized on XanTec’s proprietary ultra-low-background polycarboxylate HC surface. This new surface is a versatile tool for various applications in clinical and pharmaceutical COVID-19 R&D and available for the following SPR instruments:

* For inquiries please contact the instrument manufacturer.

The C19RBDHC30M sensor chip was primarily developed for fast and label-free detection of anti-SARS-CoV-2 antibodies from patient serum for R&D purposes. As the sample matrix contains serum and is thus prone to nonspecific interactions, a highly bioinert chip coating, optimized reagents, and an adapted protocol are essential for highly specific and sensitive detection of anti-SARS-CoV-2 antibodies.

This is where all the optimized characteristics of XanTec’s bioinert polycarboxylate (HC) coating come into play compared with carboxymethyldextran (the coating that is normally used):

The SARS-CoV-2 RBD sensor chips are especially advantageous for imaging SPR (iSPR) systems (e.g., Carterra, IBIS MX96, etc.) in which many patient samples can be applied to the sensor chip surface in parallel to check for an immunological response (IgG, IgA, IgM).

Using the RBD protein in combination with the bioinert polycarboxylate surface ensures high specificity and sensitivity and also prevents false-positive results from samples from patients with earlier coronavirus infections or high nonspecific binding (Figs. 1a & b).

Figure 1a. Overlaid sensorgrams of injected COVID-19-positive and -negative diluted human serum on XanTec SARS-CoV-2 RBD sensor chip. Blue sensorgrams: COVID-19-negative; red sensorgrams: COVID-19 positive. Readout (Response 1) after washing at 1200 sec. Sensor chip: XanTec C19RBDHC30M, Instrument: Reichert 4SPR.
Figure 1b. Improved signal-to-noise ratio by injection of XanTec’s washing buffer. R1 without, and R2 after washing step. P: Positive samples, N: Negative samples. The red dotted line indicates the three-fold nonspecific binding (biological noise) above which a sample is determined as COVID-19-positive after washing buffer injection. E. g., sample 2N becomes clearly negative, while sample 3P can be identified as positive. Sensor chip: XanTec C19RBDHC30M, Instrument: Reichert 4SPR.

To optimize the performance of the C19RBDHC30M sensor chip, we offer the following adapted reagents:


With the COVID-19 RBD sensor chip and tailored reagents, XanTec brings considerable added value to pharmaceutical, vaccine and diagnostic research and underlines its leadership in the field of SPR sensor chip technology.

For further information regarding XanTec’s product range contact our team at