Thermo Scientific Pierce Dextran Desalting Columns are ready-to-use, disposable, gel-filtration columns for separating proteins and other macromolecules from low-molecular weight buffer salts and reagents.

• Stable in water, salt solutions, organic solvents and alkaline or acidic conditions
• Excellent flow properties
• Heat-stable

Pierce Dextran Desalting Columns (5K MWCO) are plastic columns that are pre-packed with crosslinked beaded dextran for protein desalting and buffer-exchange applications based on a molecular-weight cutoff (MWCO) of 5000.

Gravity-flow gel filtration involves the chromatographic separation of molecules of different dimensions based ontheir relative abilities to penetrate into a suitable stationary phase. A chromatographic matrix, usually consisting of very small, uncharged porous particles in an aqueous solution, is packed into a column and then used for the separation. Different levels of separation can be achieved based on the pore size of the medium packed into the column. The medium can be chosen to totally exclude proteins or large molecules, while still including small solutes. Large molecules are excluded from the internal pores of the gel and emerge first from the column. The smaller molecules are able to penetrate the pores, then progress through the column at a slower rate. These smaller molecules are subsequently flushed through the column with additional buffer volume.

Desalting and buffer exchange are two of the most widely used applications of gel filtration chromatography.

The wet diameter of these dextran desalting beads is 50 to 150 µM. The resin has good rigidity for easy handling and excellent flow properties. Dextran is stable in water, salt solutions, organic solvents and alkaline or weakly acidic solutions. It is heat-stable and can be autoclaved dry or in solution at a neutral pH for 30 minutes at 120˚C without affecting its chromatographic properties.