Polynucleotide-agarose

When used to separate polynucleotides, agarose is used at concentrations in the range of 0.3-2% (w/v). Agarose concentration determines pore size within the gel matrix, which in turn determines the optimal range of polynucleotide sizes that can be efficiently separated. The following table is a convenient way to determine the concentration of agarose to use for various DNA separations (Mitra, 2003) ... 

Double-stranded polynucleotides Ethidium bromide Very sensitive widely used with agarose gels... 

DNA Agarose Calf thymus DNA DNA/RNA polymerase, polynucleotide kinase Endonucleases and exonucleases Pharmacia... 

Polynucleotide-ogarose. As discussed above, oligo-dT columns are used for purification of mRNA. Poly-U columns may also be used instead of oligo-dT. Similarly, specific polynucleotide sequences covalently linked to agarose may be used to purify transcription factors and other DNA-binding proteins. 

Restriction enzyme activities can be assayed by various methods including gel visualization assay, polynucleotide kinase exchange assay (36), and exonuclease-coupled assay (37). By far the most common of all assay methods is the visualization by EtBr staining of the digestion products separated by electrophoresis in an agarose gel (30,38). This method is straightforward and enables the detection of contaminating activities of endo- and exonucleases. 

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