Recombinant Protein;500UG;SARS-CoV-2 S protein (HV69-70del, Y144del, N501Y, A570D, D614G, P681H, T716I, S982A, D1118H), His Tag (SPN-C52H6) is the ectodomain of SARS-CoV-2 S protein that contains AA Val 16 - Pro 1213 (Accession # QHD43416.1) and HV69-70del, Y144del, N501Y, A570D, D614G, P681H, T716I, S982A, D1118H mutations, which have become increasingly common in SARS-CoV-2 viruses from around the world. The recombinant protein is expressed from human 293 cells (HEK293) with T4 fibritin trimerization motif and a polyhistidine tag at the C-terminus. Proline substitutions (F817P, A892P, A899P, A942P, K986P, V987P) and alanine substitutions (R683A and R685A) are introduced to stabilize the trimeric prefusion state of SARS-CoV-2 S protein and abolish the furin cleavage site, respectively. HV69-70del / Y144del / N501Y / A570D / D614G / P681H / T716I / S982A / D1118H mutations were identified in the SARS-CoV-2 variant (known as 20B/501Y.V1, VOC 202012/01, or B.1.1.7 lineage) which emerged