Description：Recombinant COVID-19 Spike Protein is produced by mammalian expression system and the target gene encoding Gln14-Trp1214(Arg685Ala) is expressed with a 6His tag at the C-terminus.Form：Liquid in a 0.2 μm filtered solution of PBS, pH 7.4.Alternative Names：2019-nCov S protein; 2019-nCoV Spike glycoprotein; 2019-nCoV S glycoprotein Entrez Gene (Human)： QHD43416.1; 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.