COVID-19 Binding Assays

SARS-CoV-2 Inhibitor Screening ELISA kits

COVID-19 binding assays enable rapid, high throughput, and in vitro screening of potential inhibitors of Spike-receptor complexes that facilitate SARS-CoV-2 viral entry. These patented enzyme-linked immunosorbent assays (ELISAs) use a 96-well plate and produce a colorimetric read-out for easy data interpretation. RayBiotech offers binding assays for studying interactions between the SARS-CoV-2 Spike protein (wild-type & mutants) and key host cell receptors, including angiotensin I converting enzyme 2 (ACE2), neuropilin-1 (NRP1), and tyrosine-protein kinase receptor UFO (AXL). RayBio® COVID-19 binding assays are a perfect solution for laboratories with a limited budget. In addition, the kits can be handled safely at biosafety level 1 (BSL1), although the BSL requirements may change based on the sample type being tested. Spike-ACE2 inhibitors can also be screened in cell culture with our COVID-19 Pseudovirus Service.

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How It Works

Kit Features

• High throughput: Screen hundreds of potential inhibitors of the Spike-receptor complexes simultaneously
• Rapid: Get results in 5 hours!
• Simple to use: Colorimetric assay requires a common microplate reader capable of measuring absorbance at 450 nm
• Compatible with various sample types: Small molecules, antibodies, sera, and peptides

Contents of Kit

• 96-well microplate (12 strips x 8 wells) pre-coated with the natural ligand for the recombinant protein
• Wash buffer concentrate (20x)
• Assay diluent (5x)
• Recombinant protein
• Detection antibody or HRP-conjugated detection antibody specific to the recombinant protein
• HRP-conjugated anti-detection antibody (included in some kits)
• TMB One-Step Substrate Reagent
• Stop Solution

Full testing service is available. E-mail [email protected] to learn more.

Spike Mutants

Multiple mutations of the wild type SARS-CoV-2 Spike protein (Accession no. QHD43416) have emerged since the COVID-19 pandemic began. RayBiotech offers inhibitor screening ELISA kits featuring the Spike RBD protein with mutations that appear in major SARS-CoV-2 variants of concern. The binding of the RBD to ACE2 enables viral entry.

SARS-CoV-2 Variant Classifications and Definitions

RayBiotech spike RBD mutant binding assays include:

N501Y mutant: present in Alpha, Beta, and Gamma variants (B.1.1.7, B.1.351, P.1)
Spike RBD protein with one amino acid mutation: N501Y.

E484K mutant: present in Beta and Gamma variants (B.1.351, P.1)
Spike RBD protein with one amino acid mutation: E484K.

Beta variant mutations (B.1.351)
Spike RBD protein with three amino acid mutations: K417N, E484K, N501Y.

Gamma variant mutations (P.1)
Spike RBD protein with three amino acid mutations: K417T, E484K, N501Y.

D614G mutant: present in Alpha, Beta, and Gamma variants (B.1.1.7, B.1.351, P.1)
Spike RBD protein with one amino acid mutation: D614G.

Alpha variant mutations (B.1.1.7)
Spike S1 protein mutations include a deletion in NTD at HV69-70 and two amino acid mutations in RBD: N501Y, D614G.

Patents

U.S. patent: 11,105,804

Citations

1. Boroduske, Anete et al. "Wild Sambucus nigra L. from north-east edge of the species range: A valuable germplasm with inhibitory capacity against SARS-CoV2 S-protein RBD and hACE2 binding in vitro." Industrial crops and products vol. 165 (2021): 113438. doi:10.1016/j.indcrop.2021.113438 [view publication]
   • Product: CoV-SACE2-1
   • Sample Type: Fruit extract
2. Olaleye, Omonike A et al. "Discovery of Clioquinol and analogues as novel inhibitors of Severe Acute Respiratory Syndrome Coronavirus 2 infection, ACE2 and ACE2 - Spike protein interaction in vitro." Heliyon vol. 7,3 (2021): e06426. doi:10.1016/j.heliyon.2021.e06426 [view publication]
   • Product: CoV-SACE2-1
   • Sample Type: Small molecule
3. Olaleye, Omonike A et al. "Ambroxol Hydrochloride Inhibits the Interaction between Severe Acute Respiratory Syndrome Coronavirus 2 Spike Protein’s Receptor Binding Domain and Recombinant Human ACE2." bioRxiv 2020.09.13.295691; doi: https://doi.org/10.1101/2020.09.13.295691 [view publication]
   • Product: CoV-SACE2-1
   • Sample Type: Small molecule
4. Tsukinoki, Keiichi et al. "Detection of cross-reactive IgA against SARS-CoV-2 spike 1 subunit in saliva." medRxiv 2021.03.29.21253174; doi: https://doi.org/10.1101/2021.03.29.21253174 [view publication]
   • Product: CoV-SACE2-1
   • Sample Type: Purified antibody