Cat#:RP-5911H;Product Name:Recombinant Streptavidin Protein(37-159)(His Tag);Background:Streptavidin is a 52.8 kDa protein purified from the bacterium Streptomyces avidinii. Streptavidin homo-tetramers have an extraordinarily high affinity for biotin (also known as vitamin B7 or vitamin H).Streptavidin is used extensively in molecular biology and bionanotechnology. The strong streptavidin-biotin bond can be used to attach various biomolecules to one another or onto a solid support.Pretargeted immunotherapy uses streptavidin conjugated to a monoclonal antibody against cancer cell-specific antigens followed by an injection of radiolabelled biotin to deliver the radiation only to the cancerous cell.;Description:Streptavidin Recombinant produced in E. coli is a single polypeptide chain containing 148 amino acids (37-159) and having a molecular mass of 15.6kDa. Streptavidin is fused to a 25 amino acid His-tag at N-terminus & purified by proprietary chromatographic techniques.;Source:E.coli.;AA Sequence:MGSSHHHHHH SSGLVPRGSH MGSHMAEAGI TGTWYNQLGS TFIVTAGADG ALTGTYESAV GNAESRYVLT GRYDSAPATD GSGTALGWTV AWKNNYRNAH SATTWSGQYV GGAEARINTQ WLLTSGTTEA NAWKSTLVGH DTFTKVKP.;Purity:Greater than 90% as determined by SDS-PAGE.;Formulation:The recombinant streptavidin protein solution (0.25mg/ml) contains 20mM Tris-HCl buffer (pH 8.0), 0.15M NaCl and 20% glycerol.;Stability:Recombinant Streptavidin Proteins are stable for up to 1 year from date of receipt at -70℃;Storage:Store recombinant Streptavidin protein at 4°C if entire vial will be used within 2-4 weeks. Store, frozen at -20°C for longer periods of time. For long term storage it is recommended to add a carrier protein (0.1% HSA or BSA). Avoid repeated freeze-thaw cycles.;References:Weber, P. C. (1989). "Structural Origins of High-Affinity Biotin Binding to Streptavidin". Science. 243 (4887): 85–8.;