Affinity chromatography beaded celluloses

Membranes have been used for affinity chromatography in various formats, such as stacked sheets, in rolled geometries, or as hollow fibers. Materials that are commonly used for these membranes are cellulose, polysulfone, and polyamide. Because of their lack of diffusion pores, the surface area in these materials is as low as it is in nonporous beads. However, the flat geometry and shallow bed depth of membranes keep the pressure drop across them to a minimum degree. This means that high flow rates can be used, which makes these membranes especially well-suited for capturing proteins from dilute feed streams. 

The ultimate combination of HPLC and AC is effectuated in High Performance Affinity Chromatography (HPAC).47 The development of this hybrid technique was highly assisted by the use of modified silica. Traditional polysaccharide supports may not be used for HPAC, because they lack mechanical stability to withstand the high pressure drops, inherent to this method. Modified silica beads are well suited. These may be coated with active groups as in normal AC applications. Additionally, if the separation requires the use of an organic stationary phase, the silica beads are modified with a silane or polymer with subsequent deposition of polysaccharides such as dextrans, agarose or cellulose.50... 

Use of Highly Porous Bead Cellulose with Attached Bacitracin for Affinity Chromatography of a Microbial Proteinase J, TurkovA, M.J. Benes, M. Kiihn, V.M. Stepanov, and L.A. Lyublinskaya... 

USE OF HIGHLY POROUS BEAD CELLULOSE WITH ATTACHED BACITRACIN FOR AFFINITY CHROMATOGRAPHY OF A MICROBIAL PROTEINASE... 

Stamberg, J., Peska, J., Dautzenberg, H., and Philipp, B. 1982, Bead cellulose, "Analytical Chemistry S)nnposia Series, Vol. 9, Affinity Chromatography and Related Techniques", T.C.J Gribnau, J, Visser and R.J.F, Nivard, eds., Elsevier, Amsterdam, p. 131. 

Celluloses in fibre, microgranular, bead and sheet form suitable for chromatographic applications are commercially available. The main use of this type of material is as a base matrix for ion exchange, CM and DEAE cellulose and affinity chromatography (Whatman). 

RNA to be studied can be selectively purified by hybridization on solid supports or in agarose chromatography or centrifugation. Conventional solid phases have included nitrocellulose or activated cellulose and affinity columns. Recently, nylon or, particularly, paramagnetic beads have become very useful since hybridization is much faster, reaches completion rapidly, leaches less capture nucleic acid and they allow convenient washes. 

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