Gel filtration SpinColumns G-10, G-25, G-50, and G-100 are packed with Sephadex. Sephadex is a highly cross linked porous agarose particles which are covalently bonded. P-2 and P-6 SpinColumns are porous polyacrylamide beads prepared by copolymerization of acrylamide and N,N'-methylene-bis-acrylamide.
Explanation of SpinColumn Beads
Sephadex is very physically and chemically stable due to the highly cross-linked agarose matrix. The mechanical rigidity of Sephadex allows relatively viscous eluents, such as 8M urea, to run at moderate flow rates. The stability of Sephadex also allows for cetrifugation at moderate to high speeds, where protocols require moderate to high centrifugation speeds. Under normal chromatography conditions nonspecific interactions between proteins and Sephadex are negligible when using buffers with ionic strengths in the range of 0.15M to 1.5M.
P-2 and P-6 polyacrylamide spincolumns are extremely hydrophobic and essentially free of charge. These provide efficient gel filtration of sensitive compounds. The composition and lack of soluble impurities eliminate sample contamination. The consistency of bead diameter gives high resolution separation by molecular weight. The polyacrylamide columns are compatible with dilute organic acids, 8M urea, 6M guanidine-HCL, chaotropic agents, reducing agents (such as dithiothreitol and mercaptoethanol), and detergents (such as SDS, CHAPS, and TRITON® X-100. These spincolumns work best with >50mM ionic strength buffers for most protein separations, but can be used with distilled water. Miscible organic solvents may be added to the eluent used with P-2 and P-6 spincolumns. Alcohol up to 20% will not substantially alter the exclusion properties of the gel, and will in some cases enhance separation of complex mixtures of slightly water soluble small molecules such as nucleotides, peptides and tannins.