Biotin-Tagged Purification

An assortment of reagents for the purification of biotin labelled proteins are available from G-Biosciences. For single step, small and large scale affinity purifications try Immobilized Avidin Resin. With similar binding to biotin as avidin but less non-specific binding we offer Immobilized Streptavidin Resin. The advantage of streptavidin is that the lack of carbohydrates significantly reduces the amount of non-specific binding. Immobilized Streptavidin Resin is available as slurry or in a 1mL spin-column format. G-Biosciences Immobilized Monomeric Avidin Resin is designed for the simple affinity chromatography purifications of proteins, antibodies and other molecules with a biotin tag. The resin consists of monomeric subunits of avidin covalently coupled to 6% cross-linked agarose, offering a stable, reusable resin for the purification of biotinylated molecules. Monomeric avidin offers a distinct advantage over native avidin, a tetrameric molecule, and streptavidin as it has a much lower biotin binding affinity, Kd=10-7 as opposed to Kd=10-15 for native avidin.This lower binding affinity allows elution of molecules with mild elution buffers (2mM D-Biotin in 1X PBS), as opposed to the strong denaturing buffers (8M Guanidine•HCl, pH 1.5) used with native avidin.

Accurate estimation of the molar ratio of biotin conjugated to protein/antibody is easy and affordable with HOOK™ BiotinQuant™ Kit. HOOK™ Cell Surface Protein Isolation Kit uses G-Biosciences HOOK™ biotin labeling and purification technology in conjunction with our Mammalian Cell PE LB™ lysis buffer to conveniently label cell surface proteins and isolate them for further analysis, including Western blotting.

For convenience and consistency we provide Streptavidin Binding Buffer (20mM NaPO4, 0.15M NaCl (pH7.5) and Streptavidin Elution Buffer (8M Guanidine.HCl pH1.5).