Description：Recombinant COVID-19 S Protein RBD-SD1 is produced by mammalian expression system and the target gene encoding Arg319-Ser591 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 RBD Protein; 2019-nCoV Spike RBD Protein Entrez Gene (Human)： QHD43416.1; Purity：Greater than 95% as determined by reducing SDS-PAGE.Chemical Structure：RVQPTESIVR FPNITNLCPF GEVFNATRFA SVYAWNRKRI SNCVADYSVL YNSASFSTFK CYGVSPTKLN DLCFTNVYAD SFVIRGDEVR QIAPGQTGKI ADYNYKLPDD FTGCVIAWNS NNLDSKVGGN YNYLYRLFRK SNLKPFERDI STEIYQAGST PCNGVEGFNC YFPLQSYGFQ PTNGVGYQPY RVVVLSFELL HAPATVCGPK KSTNLVKNKC VNFNFNGLTG TGVLTESNKK FLPFQQFGRD IADTTDAVRD PQTLEILDIT PCSHHHHHHQuality Control：Endotoxin: Less than 0.1 ng/µg (1 IEU/µg) as determined by LAL test.Directions for Use：Always centrifuge tubes before opening. Do not mix by vortex or pipetting. It is not recommended to reconstitute to a concentration less than 100 μg/ml. Please aliquot the reconstituted solution to 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.