The SARS-CoV-2 Spike RBD-ACE2 Blocking Antibody Detection ELISA Kit allows for the detection of antibodies (or small molecules) that block the interaction between the host receptor-binding domain (RBD) of the SARS-CoV-2 spike protein and ACE2. In this assay, SARS-CoV-2 spike RBD protein linked to HRP (RBD-HRP) is pre-incubated with the sample and controls, allowing blocking antibodies present in the sample to bind to the RBD-HRP. These pre-incubated mixtures are then added to microwell plates coated with ACE2 protein. The RBD-HRP is captured by ACE2 in the well to varying degrees depending on the blocking activity present in each sample. The wells are then washed to remove unbound material. HRP substrate, TMB, is added to develop color. The magnitude of optical density for this developed color is inversely proportional to the ability of the sample to block the interaction between SARS-CoV-2 spike RBD and ACE2 proteins. For example, if no blocking activity is present in the sample, the RBD-HRP will be able to bind to ACE2 on the microwell plates, resulting in high signal. Conversely, samples with high blocking activity will prevent the RBD-HRP from binding to ACE2 on the microwell plates, resulting in low signal. This kit is designed to detect blocking antibodies present in human serum/plasma samples. However, this kit may also be used to assess the blocking activity of non-human antibodies and small molecules. In the latter scenarios (for non-human antibodies and small molecules), the user will have to determine the appropriate dilution/concentration of their samples to use, along with running the proper controls. -
