Recombinant SARS-CoV-2 Spike protein, S1 subunit encompassing amino acids 16-685. This protein corresponds to SARS-CoV-2 Variant B.1.351, also known as variant Beta originally identified in South Africa, and contains mutations L18F, D80A, D215G, R246I, K417N, E484K, N501Y, and D614G. It also contains a C-terminal Avi-Tag™ followed by a C-terminal His-tag (6xHis). The recombinant protein was affinity purified.