Description：Recombinant COVID-19 S protein RBD Protein is produced by our mammalian expression system and the target gene encoding Arg319-Phe541 (G339D, S371L, S373P, S375F, K417N, N440K, G446S, S477N, T478K, E484A, Q493R, G496S, Q498R, N501Y, Y505H) is expressed with a 6His tag at the C-terminus. G339D, S371L, S373P, S375F, K417N, N440K, G446S, S477N, T478K, E484A, Q493R, G496S, Q498R, N501Y and Y505H mutations were identified in the COVID-19 variant (known as Omicron/B.1.1.529 lineage) which emerged in South Africa.Form：Liquid in a 0.2 μm filtered solution of PBS, pH 7.4.Alternative Names：SARS-CoV-2 RBD Protein; SARS-CoV-2 Spike RBD Protein; SARS-CoV-2 S Protein RBD Entrez Gene (Human)： 43740568; SwissProt (Human)： P0DTC2; Purity：Greater than 95% as determined by reducing SDS-PAGE.Directions for Use：Please minimize freeze-thaw cycles.Quality Control：Endotoxin: Less than 0.1 ng/µg (1 IEU/µg) as determined by LAL test.Storage/Stability：Store it at -20°C to -80°C for one year. It is recommended that the protein be aliquoted for optimal storage. Avoid repeated freeze-thaw cycles.

• 
  Greater than 95% as determined by reducing SDS-PAGE.
• 
  Loaded Human ACE-2 on Protein A Biosensor, can bind Recombinant COVID-19 S Protein RBD (Omicron, B.1.1.529) with an affinity constant of 6.32 nM as determined in bioactivity assay.
• 
  Loaded Anti-COVID-19 S1 mAb on Protein A Biosensor, can bind Recombinant COVID-19 S Protein RBD (Omicron, B.1.1.529) with an affinity constant of 19.5 nM as determined in bioactivity assay.