SARS-CoV-2 (Delta) Spike Trimer Protein is expressed from human 293 cells (HEK293). It contains AA Arg 319 - Lys 537(Accession # QHD43416.1 (T19R, G142D, EF156-157del, R158G, L452R, T478K, D614G, P681R, D950N, R683A, R685A, F817P, A892P, A899P, A942P, K986P, V987P)).