Recombinant SARS-CoV-2 S protein RBD Protein is produced by our Mammalian expression system and the target gene encoding Arg319-Phe541 (G339D, S371F, S373P, S375F, T376A, D405N, R408S, K417N, N440K, L452R, S477N, T478K, E484A, F486V, Q498R, N501Y, Y505H) is expressed with a 6His tag at the C-terminus. The mutations were identified in the SARS-CoV-2 variant (known as BA.4 and BA.5 lineages) which emerged in the South Africa.