SARS-CoV-2 S protein RBD (K417N,E484K,N501Y), Fc Tag (SPD-C5256) is expressed from human 293 cells (HEK293). It contains AA Arg 319 - Lys 537 (Accession # QHD43416.1 (K417N, E484K, N501Y)). The K417N, E484K, N501Y mutations were identified in the SA 1 * 100 µG