Spike S1 RBD (B.1.1.529 BA.1, Omicron Variant) (SARS-CoV-2): ACE2 Inhibitor Screening Colorimetric Assay Kit

Catalog #
$1,095 *
Size: 96 reactions
*US Pricing only. For international pricing, please contact your local distributor.

The Spike S1 RBD (B.1.1.529 BA.1, Omicron Variant) (SARS-CoV-2): ACE2 Inhibitor Screening Colorimetric Assay Kit is designed for screening and profiling inhibitors or neutralizing antibodies of the interaction between the Omicron variant SARS-CoV-2 Spike RBD and human ACE2. 

The assay requires only a few steps. First, SARS-CoV-2 Spike RBD (B.1.1.529 BA.1, Omicron Variant) is coated on a 96-well plate overnight. After washing and blocking, the protein is pre-incubated with an inhibitor or neutralizing antibody. Upon subsequent incubation with Biotin-ACE2, the plate is treated with Streptavidin-HRP followed by addition of a colorimetric HRP substrate to produce color, which can be quenched and measured using a UV/Vis microplate reader.

Assay Principle

Spike S1 RBD

Sars-cov-2 B.1.1.529, South Africa variant, colorimetric Spike RBD kit, B.1.1.529 inhibitor kit, Sublineage BA.1
Product Info
Storage and Usage
Assay Kit Format
Supplied As
This kit comes in a convenient 96-well format, with Biotinylated-ACE2, purified Spike RBD (B.1.1.529 BA.1, Omicron Variant) protein (Avi-His-tagged), Streptavidin-HRP, and assay buffers for 100 reactions.
Materials Required But Not Supplied

PBS (Phosphate buffered saline)
1N HCl (aqueous)
Rotating or rocker platform
UV/Vis spectrophotometer microplate reader capable of reading absorbance at 450 nm*

Catalog # Name Amount Storage
101356 Spike S1 RBD (B.1.1.529 BA.1, Omicron Variant), Avi-His-Tag (SARS-CoV-2)* 5 µg -80°C
100665 ACE2, His-Avi-Tag, Biotin labeled * 2 x 5 µg -80°C
79311 3x Immuno Buffer 1 50 ml -20°C
79728 Blocking Buffer 2 50 ml +4°C
79742 Streptavidin-HRP 10 µl +4°C
79651 Colorimetric HRP substrate 10 ml +4°C
79964 Transparent 96-well microplate 1 Room Temp

*The initial concentration of both ACE2 and Spike RBD is lot-specific and will be indicated on the tube containing the protein.


The COVID-19 pandemic is caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). The Spike glycoprotein is expressed on the surface of the virus as a trimer. Each Spike protein consists of two subunits, S1 and S2, and the S1 subunit contains the receptor binding domain (RBD) which recognizes and attaches to the ACE2 receptor found on the surface of type I and II pneumocytes, endothelial cells, and ciliated bronchial epithelial cells. SARS-CoV-2 Variant B.1.1.529 BA.1, also known as Omicron variant, was originally discovered in South Africa and has recently become a global variant of concern.

Drugs targeting the interaction between SARS-CoV-2 Spike protein and human ACE2 may offer some protection against viral infection. The SARS-CoV-2 Spike RBD (B.1.1.529 BA.1, Omicron Variant) protein in this kit consists of the RBD region of the S1 protein, which includes the ACE2 binding site.