SEPHADEX G-50 Chemical Properties,Uses,Production
Sephadex G-50 Superfine is a well established gel filtration medium for desalting and buffer exchange of biomolecules >30 000 molecular weight. The Superfine´s small bead size give higher efficiency.
- Quickly desalts, removes contaminants and transfers to a new buffer in a single step.
- Suitable for purification of DNA from small molecules by gel filtration
- Small bead size for shorter diffusion distances
- Smallest bead size in the Sephadex G-50 range
Sephadex is a gel filtration medium prepared by crosslinking dextran with epichlorohydrin. Different types of Sephadex differ in their degree of cross-linking and hence in their degree of swelling and their molecular fractionation range. Sephadex G-50 is one of five different G-types ranging from G-10 for small molecules to G-75 for larger molecules. Sephadex G-50 is available in 4 different particle sizes (Coarse, Medium, Fine & Superfine) and Superfine has the smallest bead size for higher efficiency with shorter diffusion distances. Coarse and Medium are are preferred for large scale group separations where high flow rates and low operating pressures are required.
The media used for gel exclusion chromatography include dextran (Sephadex™), polyacrylamide (Bio-Gel P™) and dextran-polyacrylamide (Sephacryl™) and agarose (Sepharose™ and BioGel A™). Each is available with a variety of different ranges of pore size in the beads, permitting separation of macromolecules of different size.
A gel with a smaller range of pore sizes (and hence a smaller range over which it can separate macromolecules on the basis of their size) will give a higher resolution; a gel with a wider range will give lower resolution, but will permit fractionation of a larger range of sizes as an initial step when the approximate molecular mass of the enzyme is not known.
The particle size of the gel beads (the mesh size) also affects resolution; smaller beads permit higher resolution, but a lower flow rate through the column (and hence a slower separation).
The table shows the useful range for the most commonly used gel filtration media - the lower and upper molecular sizes (in kDa) over which they can be used to separate macromolecules. The upper limit is known as the exclusion limit of the gel - the size above which proteins will elute in the void volume of the column.
SEPHADEX G-50 Preparation Products And Raw materials