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Electrophoresis of DNA in Agarose Gels, Polyacrylamide Gels and in Free Solution

Nancy C Stellwagen

Electrophoresis. 2009 Jun;30 Suppl 1(Suppl 1):S188-95.

PMID: 19517510

Abstract:

This review describes the electrophoresis of curved and normal DNA molecules in agarose gels, polyacrylamide gels and in free solution. These studies were undertaken to clarify why curved DNA molecules migrate anomalously slowly in polyacrylamide gels but not in agarose gels. Two milestone papers are cited, in which Ferguson plots were used to estimate the effective pore size of agarose and polyacrylamide gels. Subsequent studies on the effect of the electric field on agarose and polyacrylamide gel matrices, DNA interactions with the two gel matrices, and the effect of curvature on the free solution mobility of DNA are also described. The combined results suggest that the anomalously slow mobilities observed for curved DNA molecules in polyacrylamide gels are primarily due to preferential interactions of curved DNAs with the polyacrylamide gel matrix; the restrictive pore size of the matrix is of lesser importance. In free solution, DNA mobilities increase with increasing molecular mass until leveling off at a plateau value of (3.17 +/- 0.01) x 10(-4) cm2/V s in 40 mM Tris-acetate-EDTA buffer at 20 degrees C. Curved DNA molecules migrate anomalously slowly in free solution as well as in polyacrylamide gels, explaining why the Ferguson plots of curved and normal DNAs containing the same number of base pairs extrapolate to different mobilities at zero gel concentration.

Chemicals Related in the Paper:

Catalog Number Product Name Structure CAS Number Price
AP9003058-B Polyacrylamide Polyacrylamide 9003-05-8 Price
IAR42411167 Tris Acetate-EDTA buffer Concentrate Tris Acetate-EDTA buffer Concentrate Price
IAR424674 Fluorescein-α-D-galactosamine polyacrylamide Fluorescein-α-D-galactosamine polyacrylamide Price
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