Exclusion limit agarose gels

Mercapto- 5-SH)-polycy tidy lie acid has been shown by Bardos et al.55 to block the DNA-directed RNA synthesis at 1/2 to 1/50 of the concentration of the unmodified DNA template used in the reaction. This mercapto derivative of polycytidylic acid (MPC) has been prepared by partial thiolation of polycytidylic acid (PC) according to the general procedure of Bardos et al.56> 57> the thiolated compound was gel-filtered through a Sephadex column and subsequently, through an Agarose-1.5 m (Bio-Gel A-l.5 m, exclusion limit 1,5000.000 mol. wt., Bio-Rad Labs.) column, then lyophilized and redissolved in 0.1 M Tris-buffer58). This compound (conversion of 9.5% of the cytidylate units to 5-mercaptocytidylate) was studied in the DNA-polymerase system of oncorna viruses. 

Gel filtration with polyacrylamide (mol wt exclusion limit from 3000 to 300,000) and agarose gel (mol wt... 

The exclusion limits of agarose gels are so high that they find their biggest use in SEC fractionation of protein complexes and molecules with extended structures, eg, polysaccharides and also for the synthesis of composite gel media as described below. 

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