Recombinant SARS-CoV-2 Spike protein, RBD (Receptor Binding Domain) encompassing amino acids 319-541. This protein corresponds to SARS-CoV-2 Variant B.1.1.7, also known as variant Alpha originally discovered in the United Kingdom, and contains mutation N501Y. It also contains a C-terminal Avi-Tag™ followed by a His-tag (6xHis). The recombinant protein was affinity purified.