This antibody is a humanized monoclonal antibody which recognizes SARS-CoV-2 spike RBD and the full-length spike proteins in the native trimeric conformation. This antibody is derived from rabbit monoclonal C-A11 neutralizing antibody (BPS Bioscience, #101024). It cross-reacts with the wildtype as well as the B.1.617.2 (Delta Variant), B.1.617.2.1 (Delta PLUS Variant), B.1.1.7 (Alpha Variant) RBDs and spike protein trimers [Table of variants]. The human ACE2 receptor is found on the surface of type I and II pneumocytes, endothelial cells, and ciliated bronchial epithelial cells. ACE2 is known to mediate infection through direct binding of the SARS-CoV-2 Sike protein. This neutralizing antibody has been functionally tested using BPS Bioscience Spike RBD: ACE2 Inhibitor Screening Kits (available for purchase).