Anti-SARS-CoV-2 Antibodies Bind to the Coronavirus Delta Variant

In our previous blog post, we reported that many of our anti-SARS-CoV-2 antibodies bind to the most prominent coronavirus variants which emerged early during the pandemic (such as the so-called British (B.1.1.7), South African [B.1.351 (501Y.V)] and Brazilian variants (B1.1.24 / P.1)).

Now, we are pleased to report the results of our binding assays of some of our most popular anti-coronavirus antibodies with the Delta variant (the so-called Indian variant) of the SARS-CoV-2 Spike protein. Most of the tested clones show excellent cross-reactivity with the Delta spike mutant, however, some clones do not bind this variant (Figure 1 and 2).

This, together with our previous data on binding to other coronavirus mutants, should be taken into consideration when selecting clones or clone-combinations, which can allow for both detection of coronavirus regardless of its form and selective identification of particular mutant variants (or wild-type version (Wuhan)) (Table 1).

Our anti-coronavirus clones CV1, CV30, Sb#15, EY6A and CR3022 are available in our catalog in a wide variety of engineered formats, designed to open up new experimental possibilities for in vitro and in vivo use. Some of the formats include:

  • Human IgG1, IgG2, IgG3, IgG4, IgA, IgM and IgE for use in neutralization assays and as serological controls
  • Rabbit, mouse, cat and ferret formats for detection applications, co-labeling studies and animal model research
  • Human and mouse Fab and Fab2 formats with His-tags, for applications where antibody fragments are desirable and for site-specific functionalization
  • Human IgG1 and mouse IgG2b Fc Silent™ formats, which are aimed at discerning Fc-dependent and Fc-independent effector functions and facilitating research into the role of antibody-dependent enhancement (ADE)

Learn more about each antibody format here or contact us if you are looking for these clones in a different format. You can also find our full collection of anti-coronavirus antibodies on our website here.


Figure 1. ELISA using anti-SARS-CoV-2 Spike antibodies with the Delta Spike variant (B.1.617.2; Indian mutant). ELISA plate was coated with the Delta SARS-CoV-2 Spike protein (REC31975; The Native Antigen Company) at 2.5 µg/ml. The antibodies CR3022 (Ab01680), CV1 (Ab02018), CV30 (Ab02019) and Sb#15 (Ab02013), EY6A (Ab02057) , 4-4-20 (negative isotype control) were conjugated to HRP and titrated on a 3-fold serial dilution starting at 3000 ng/ml. All antibodies apart from the isotype control bound to the SARS-CoV-2 Delta Spike variant.


Clone IDClone NameAntigenB.1.1.7 (UK variant)B.1.351 (501Y.V2; South African variant)B1.1.24 / P.1 (Brazilian variant)B1.617.1 (Delta/Indian variant)
Ab01680CR3022COVID-19 & SARS-CoV S glycoprotein
Ab02018CV1Spike Protein
Ab02019CV30Spike Protein (RBD)
Ab02013Sb#15Spike protein (RBD)No binding observedNo binding observed
Ab02057EY6ASpike protein
Ab02061Ty1Spike proteinNo binding observedNot yet determinedNot yet determined
Pr00439Recombinant Human
ACE2-IgG Fc (LALA)-Fusion Protein
Spike RBD

Table 1. Chosen anti-coronavirus antibodies and their binding to three major SARS-CoV-2 Spike variants assessed by ELISA. ✓ = binding.