Date of this Version
Improved cellulosic beads for use as supports in bioaffinity chromatography are produced by dissolution of cellulose in a chaotropic cellulose solvent, formation of the dissolved cellulose into droplets, and immersion of the droplets into a non-solvent capable of solvent interchange with the cellulose solvent to form generally spherical porous cellulose beads of narrow particle size distribution. The beads formed are preferably made with cellulose having a degree of polymerization between 100 and 200, and the resulting beads when saturated with water without drying contain between 1% and 7% cellulose by weight and have a particle size of at least about 0.3 mm. The beads can be activated by a suitable activation method, and specific bioaffinity ligands are bound to the active sites in the beads. The beads reacted ligands, the beads then used in bioaffinity chromatography to isolate specific bioaffinity molecules having molecular weights between 5,000 and 500,000 from complex solutions. The beads are particularly useful in bioaffinity chromatography of antibodies, therapeutic proteins, enzymes, and other high molecular weight proteins. The cellulose beads have similar properties to agarose beads used in the prior art for bioaffinity chromatography of high molecular weight proteins, but the cellulosic beads of the present invention have much greater mechanical strength and resist crushing under higher column flow rates without chemical cross linking are much cheaper to produce than prior art agarose and dextran beads.