Method of preparing a separation matrix
View Patent ↗The present invention relates to a method of preparing an insoluble separation matrix, which method comprises salt-treatment of a polysaccharide gel followed by cross-linking of the polysaccharide polymers. In one embodiment, the method comprises providing an aqueous solution of a gelatable native polysaccharide; lowering the temperature of the polysaccharide solution to a value below its gelling point; salt-treatment by adding at least one salt to the resulting polysaccharide; and cross-linking the salt-treated polysaccharide. The polysaccharide may be prepared e.g. into particles, membranes or monoliths.
1. A method of preparing a separation matrix comprising:
(a) providing an aqueous suspension of particles comprised of gelled native polysaccharide;
(b) salt-treatment of the suspended particles by adding at least one salt; and
(c) cross-linking of the salt-treated particles;
wherein the salt(s) are added up to a salt concentration in the suspension in the range of 0.5 to 1.3 M, and wherein the temperature during the salt-treatment is in the range of 94-98° C.
2. The method of claim 1 , wherein the polysaccharide is agarose.
3. The method of claim 1 , wherein the anion of the salt added in step (b) is a sulphate.
4. The method of claim 1 , wherein the cation of the salt is selected from the group consisting of Mg; Na; K; Li; and Cu.
5. The method of claim 4 , wherein the cation of the salt is selected from the group consisting of Mg and Na.
6. The method of claim 1 , wherein the salt is MgSO 4 .
7. The method of claim 1 , wherein the temperature during the salt treatment is about 96° C.
8. The method of claim 1 , wherein the polysaccharide particles of step (a) have been prepared by emulsification in an organic solvent.
9. The method of claim 8 , wherein the particles are washed after the emulsification.
10. The method of claim 1 , additionally comprising a step of attaching chromatography ligands to hydroxyl groups of the gelled polysaccharide.
11. A cross-linked polysaccharide separation matrix produced by the method of claim 1 .
12. The matrix of claim 11 , wherein the available pore volume corresponds to a K av value for a dextran of 110 kD of at least 0.5.
13. A chromatography column comprising the separation matrix of claim 11 .
14. A method of preparing a separation matrix comprising:
(i) providing an aqueous solution of a gelatable native polysaccharide;
(ii) lowering the temperature of the polysaccharide solution to a value below its gelling point;
(iii) salt-treatment by adding at least one salt selected from sulphate or phosphate salt to the polysaccharide resulting from (ii); and
(iv) cross-linking the salt-treated polysaccharide;
wherein the salt(s) are added up to a salt concentration in the range of 0.5 to 1.3 M, and wherein the temperature during the salt-treatment is in the range of 94-98° C.
15. A cross-linked polysaccharide separation matrix produced by the method of claim 14 .
16. The matrix of claim 15 , which is a membrane or a monolith.