Agarose gels molecular weight determination

Sepharose (e.g. Sepharose CL and Bio-Gel A) is a bead form of agarose gel which is useful for the fractionation of high molecular weight substances, for molecular weight determinations of large molecules (molecular weight > 5000), and for the immobilisation of enzymes, antibodies, hormones and receptors usually for affinity chromatography applications. 

Polypeptide Chain Molecular Weight Determination by Gel Permeation Studies on Agarose Columns in 6M Guanidinium Chloride... 

Gel permeation studies on agarose-GuHCl columns provide for high resolution and accurate molecular weight determination of linear randomly coiled polypeptide chains. For nonlinear random coils, gel permeation studies provide for accurate determination of the effective hydrodynamic radius of the components. 

The gels usually employed for this purpose are 4% (limit of molecular weight determination 10,000 to 300,000 daltons) and 6% (limit of molecular weight determination 1,000 to 80,000 daltons) agarose. 

An ideal matrix for gel filtration should consist of partides of a hydrophilic polymer, that is as inert as possible, as rigid as possible, uncharged, and of uniform size (Patel 1993). Suitable materials are naturally occurring polymers, such as agarose or dextran, which have been stabilised by chemical cross linking, and also synthetic polymers such as polyacrylamide. These materials are available as spherical partides of different diameter (10-500 pm) and pore sizes the pore size determines the range of optimal molecular weight separation (Table 4-1). 

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