Anti SARS-CoV-2 RBD mAb (Clone B38)

Anti-CoV2RBD-c2-hIgG1 Unit size Cat. code Docs Qty Price
SARS-CoV-2 Spike RBD monoclonal human IgG1 antibody (Clone B38)
100 µg

You may also need : Anti SARS-CoV-2 RBD mAb (Clone H4) | View more associated products

Specific SARS-CoV-2 Spike-RBD neutralizing recombinant antibody 

Antibody Description

Anti-CoV2RBD-c2-hIgG1 is a specific SARS-CoV-2 neutralizing recombinant monoclonal antibody (mAb) originally described as 'clone B38' [1]. It features:

  • The variable region from 'clone B38' that specifically targets the Spike receptor-binding domain (S-RBD) of SARS-CoV-2 [1]
  • The human IgG1 constant region 

SARS-CoV-2 specific neutralizing mAb (clone B38)
SARS-CoV-2 spike-specific neutralizing mAb (clone B38)

Clone B38 was isolated from a convalescent COVID-19 patient and subsequently, confirmed to specifically neutralize SARS-CoV-2, in vitro, by blocking the interaction between the SARS-CoV-2 S-RBD and the host receptor ACE2 [1].  The interaction between clone B38 and the spike-RBD was further characterized by crystallography, suggesting that the antibody sterically hinders ACE2 binding to SARS-CoV-2 [1].

Early in the pandemic, a previously characterized SARS-CoV neutralizing mAb (CR3022) against the S-RBD was rapidly found to cross-react with SARS-CoV-2 [2]. However, CR3022 does not neutralize SARS-CoV-2 possibly because, unlike clone B38, it does not target the ACE2 binding motif in the RBD [3]. Interestingly, synergistic neutralization ability was observed when clone B38 was used in combination with a different epitope-targeting antibody (clone H4) identified in the same study [1]. This makes them a potentially promising virus-targeting antibody cocktail for therapeutic and/or vaccine purposes.

InvivoGen's Anti-CoV2RBD-c2-hIgG1 mAb (clone B38) has been generated by recombinant DNA technology, produced in CHO cells, and purified by affinity chromatography, ensuring lot-to-lot reproducibility. Furthermore, Anti-CoV2RBD-c2-hIgG1 mAb (clone B38) has been functionally validated in neutralizing assays (see data below), and the absence of bacterial contamination has been confirmed by cellular assays. 


Of note, InvivoGen also offers Anti-CoV2RBD-c1-hIgG1 (Clone H4), described as another SARS-CoV-2 neutralizing mAb [1]. In-house data suggests that B38 displays better inhibition of  HEK-Blue™ hACE2 cell infection by Spike-pseudotyped lentiviral particles, and clone H4 has greater sensitivity for detection by ELISA. However, depending on your application both mAbs may be suitable for the detection of Spike-RBD and neutralization of SARS-CoV-2 infection.


Antibody applications

  • Detecting the presence of SARS-CoV-2 in culture supernatant and/or in serum (ELISA)
  • Flow cytometry binding assays 
  • Developing neutralizing antibody cocktails against SARS-CoV-2

Quality control

  • Functionally validated by ELISA using a coated Spike-RBD-His fusion peptide


Learn more on SARS-CoV-2Read our reviews discussing SARS-CoV-2



1. Wu, Y. et al. 2020. A non-competing pair of human neutralizing antibodies block the COVID-19 virus binding to its receptor ACE2. Science 368, 1274-1278.
2. Tian X. et al., 2020. Potent binding of 2019 novel coronavirus spike protein by a SARS coronavirus-specific human monoclonal antibody. Emerging Microbes & Infections. 9(1):382-385.
3. Yuan M. et al., 2020. A highly conserved cryptic epitope in the receptor-binding domains of SARS-CoV-2 and SARS-CoV. Science. DOI: 10.1126/science.abb7269.


Validation of Anti-CoV2RBD-c2-hIgG1 binding to SARS-CoV-2 RBD by ELISA
Validation of Anti-CoV2RBD-c2-hIgG1 binding to SARS-CoV-2 RBD by ELISA

Validation of binding to SARS-CoV-2 RBD by ELISA. SARS‑CoV-2 Spike-RBD-His fusion peptide (5 μg/ml) was coated onto ELISA plates overnight. A serial dilution of Anti‑CoV2RBD-c2-hIgG1 (red curve) or Anti-βGal-hIgG1 (control antibody; grey curve) was added to the pre-coated plate and incubated for 1 hour. Subsequently, binding was detected with an HRP-labelled anti-hIgG1 antibody (1/1000 dilution) and the HRP substrate OPD (o-phenylenediamine dihydrochloride). Absorbance was read at 490 nm.

Anti-CoV2RBD-c2-hIgG1 inhibits infection of HEK293 cells by Spike-pseudotyped lentiviral particles
Anti-CoV2RBD-c2-hIgG1 inhibits infection of HEK293 cells by Spike-pseudotyped lentiviral particles

Inhibition of SARS-CoV-2 spike (G614-variant) pseudotyped lentiviral particles to infect human (h)ACE2-expressing cells. Anti-CoV2RBD-c2-hIgG1 (clone B38), Anti‑COV2RBD‑c1‑hIgG1 (clone H4), or a cocktail of both mAbs was incubated with SARS-CoV-2 spike-(G614-variant)-pseudotyped lentiviral particles for 1 hour at 37°C. Following this, HEK-Blue™ hACE2 cells were added and incubated for a further 72 hours. Infection by the pseudotyped particles (GFP-expression) was then measured using flow cytometry. Data are presented as % inhibition compared to the antibody-negative control.

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Specificity: SARS-CoV-2 Spike RBD
Clonality: Monoclonal 
Source: CHO cells
Formulation: 0.2 μm filtered solution in a sodium phosphate buffer with glycine, saccharose, and stabilizing agents.
Purification: Affinity chromatography with protein G
Quality control:

  • The complete sequence of the antibody construct has been verified.
  • Antibody binding has been validated by ELISA using a coated Spike-RBD-His fusion peptide.
  • The absence of bacterial contamination (e.g. lipoproteins and endotoxins) has been confirmed using HEK-Blue™ TLR2 and HEK-Blue™ TLR4 cellular assays.
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  • 100 µg purified antibody, azide-free, and lyophilized

room temperature The product is shipped at room temperature.

store Store lyophilized antibody at -20 °C.

stability Lyophilized product is stable for at least 1 year.

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Learn more about the SARS-CoV-2 Spike protein here.

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