Theory of Gel Filtration

Separation of molecules by gel filtration. A Application of sample containing large and small molecules. B Large mole cules cannot enter gel matrix, so they move more rapidly through the column. C Elution of the large molecules. 

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Latour, LL Kleinherg, RL Mitra, PP Sotak, CH, Pore-Size Dishibutions and Tortnosity in Heterogeneous Porous Media, Journal of Magnetic Resonance Series A 112, 83, 1995. Laurent, TC KiUander, J, A Theory of Gel Filtration and Its Experimental Verification, Jonr-nal of Chromatography 14, 317, 1964. 

Rodbard, D Chrambach, A, Unified Theory of Gel Electrophoresis and Gel Filtration, Proceedings of the National Academy of Science, USA 65, 970, 1970. 

Pharmacia Biotechnology, Gel Filtration Principles and Methods, 5th ed. (1991), Pharmacia Biotechnology, S-751 82 Uppsala, Sweden, or 800 Centennial Avenue, Piscataway, NJ 08854. An excellent guide on theory, practice, and applications of gel filtration. 

The technique of gel filtration is widely used in biochemical research. Chapter 3 described the theory and applications of gel filtration to the experimental procedures of desalting, separation and purification of biomolecules, and estimation of molecular weight of biomolecules. In this experiment, gel filtration procedures will be used to study the dynamic binding of small molecules by proteins. Many of the dynamic processes occurring in biological cells and organisms are the result of interactions between molecules. Often these interactions involve one or more smaller molecules binding to a macromolecule (usually a protein or nucleic acid). 

Maximum Number of Components Resolvable by Gel Filtration and Other Elution Chromatographic Methods, J. C. Giddings, Anal. Chem., 39, 1927 (1967). Statistical Theory for the Equilibrium Distribution of Rigid Molecules in Inert Porous Networks. Exclusion Chromatography, J. C. Giddings, E. Kucera, C. P. Russell, and M. N. Myers, J. Phys. Chem., 72, 4397 (1968). 

Janson and Hedman (1) recently published an excellent review of large-scale chromatography. Many of the broad process design and operation considerations are the same for affinity chromatography as they are for ion exchange or gel filtration. Most chromatography models, however, are based on the assumption of small feed pulses with linear equilibria (such as the widely-used plate theories (2)) and are not directly useful for affinity separations. In this paper we discuss and compare experimental results with two fixed-bed adsorption models that can be used to predict the performance of affinity columns. These two models differ only in the form of the rate-... 

A detailed discussion of the principles and theory that are the fundamentals of Ion Exchange Chromatography can be found in Himmelhoch (1) and on the GE Health Care web site (2). While this is a powerful method for the purification of proteins, it should be preceded by ammonium sulfate fractionation (see Chapter 3) or followed by affinity chromatography (see Chapter 5) or gel filtration (see Chapter 3) when used to purify immunoglobulins from crude materials. This section only intends to be a short introduction to the theoretical basis of this technique. 

Gel filtration has been suggested as a means for characterizing the gross features of networks, by use of a theory that treats the network as being a random collection of infinitely long fibers.176 The fraction... 

Sephadex-Gel Filtration in Theory and Practice, Pharmacia Fine Chemicals, Upsalla, Sweden. This company also supplies yearly booklets of literature references and gel permeation chromatography. 

In the case of cross flow filtration, one can expect that the gel layer thickness and/or the surface concentration of the solute will vary with distance from the channel entrance. As a consequence, the local permeate flux will also vary with longitudinal position. In a highly recommended article, Denisov [56] presented a mathematically rigorous theory of concentration polarization in cross flow UF, which takes into account the nonuniformity of the local permeate membrane flux. He derived equations describing the pressure/ flux curve. 

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