G-Biosciences' Streptavidin Resin is designed for the single step small and large scale affinity purification of proteins and antibodies with a biotin tag

G-Biosciences' Streptavidin is a tetrameric protein containing 4 biotin binding sites. Streptavidin in many respects is similar to avidin except that it has no carbohydrate and has a slightly lower molecular weight of about 60 kDa. The solubility of streptavidin (isoelectric pH 5) in aqueous buffer is much lower than avidin, but the binding of streptavidin to biotin is similar to that of avidin. The advantage of streptavidin is that the lack of carbohydrates significantly reduces the amount of non-specific binding.

G-Biosciences' streptavidin used for immobilization on porous 6% crosslinked agarose is a recombinant form with a mass of 53 kDa and near neutral pI. The streptavidin in covalently coupled to the agarose resulting in minimal leaching and is stable over a pH range of 2-11. The Streptavidin Resin is supplied as a 50% resin slurry or in a 1 mL spin column format, and is available as resin alone or in a kit format. The kit contains: 5 mL resin, 100 mL Streptavidin Binding/Wash Buffer (20 mM NaPO₄, 0.15 M NaCl, pH 7.5), 100 mL Streptavidin Elution Buffer (8M Guanidine × HCl pH 1.5), 5 empty 1 mL spin columns and 5 empty <5 mL gravity flow columns. Specific binding and elution buffers are also offered.

Streptavidin Resin can also be used for immunoprecipitations using biotin labeled antibodies. Biotin, a 244 Da vitamin (Vitamin H) molecule, exhibits an extraordinary binding affinity for avidin (Ka=10¹⁵M¯¹) and streptavidin (Ka=10¹⁵M¯¹). Biotin and (strept) avidin interaction is rapid and once the bond is established it can survive up to 3M guanidine-hydrochloride and extremes of pH. Biotin-avidin bonds can only be reversed by denaturing the avidin protein molecule with 8M guanidine-hydrochloride at pH 1.5 or by boiling in SDS Page Sample Loading Buffer.

Kit contains:
Caps, Screw 5x
Spin Column, 1ml 5x
Empty disposable columns‐1‐5ml Medi 5x
Streptavidin Resin (10ml as 50% slurry in 20% ethanol) 1x 5ml resin
Streptavidin Binding Buffer 1x 100ml
Streptavidin Elution Buffer 1x 100ml