Description：Recombinant Human CD28 Protein is produced by mammalian expression system and the target gene encoding Asn19-Pro152 is expressed with a Fc tag at the C-terminus.Form：Lyophilized from a 0.2 μM filtered solution of PBS, pH 7.4.Gene Symbol：CD28Alternative Names：T-cell-specific surface glycoprotein CD28; TP44; CD28 Entrez Gene (Human)： 940; SwissProt (Human)： P10747; Purity：Greater than 95% as determined by reducing SDS-PAGE.Chemical Structure：NKILVKQSPM LVAYDNAVNL SCKYSYNLFS REFRASLHKG LDSAVEVCVV YGNYSQQLQV YSKTGFNCDG KLGNESVTFY LQNLYVNQTD IYFCKIEVMY PPPYLDNEKS NGTIIHVKGK HLCPSPLFPG PSKPVDDIEG RMDEPKSCDK THTCPPCPAP ELLGGPSVFL FPPKPKDTLM ISRTPEVTCV VVDVSHEDPE VKFNWYVDGV EVHNAKTKPR EEQYNSTYRV VSVLTVLHQD WLNGKEYKCK VSNKALPAPI EKTISKAKGQ PREPQVYTLP PSREEMTKNQ VSLTCLVKGF YPSDIAVEWE SNGQPENNYK TTPPVLDSDG SFFLYSKLTV DKSRWQQGNV FSCSVMHEAL HNHYTQKSLS LSPGKDirections 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. Dissolve the lyophilized protein in 1X PBS. Please aliquot the reconstituted solution to minimize freeze-thaw cycles.Quality Control：Endotoxin: Less than 0.1 ng/μg (1 IEU/μg) as determined by LAL test.Storage/Stability：Lyophilized protein should be stored at -20°C, though stable at room temperature for 3 weeks. Reconstituted protein solution can be stored at 2-8°C for 2-7 days. Aliquots of reconstituted samples are stable at -20°C for 3 months.