Description: Recombinant COVID-19 S-trimer Protein is produced by mammalian expression system and the target gene encoding Cys15-Gln1208 is expressed with two mutation sites at G614&K439 and a 6His tag at the C-terminus. Form: Liquid in a 0.2 μm filtered solution of PBS, pH 7.4. Alternative Names: S1 protein; 2019-nCoV S1 protein; coronavirus S1 Protein; cov S1 ProteinEntrez Gene (Human): QHD43416.1SwissProt (Human): P0DTC2Purity : Greater than 95% as determined by reducing SDS-PAGE.Directions for Use : Please minimize freeze-thaw cycles. 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.