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DNA electrophoresis in agarose gels: Effects of field and gel concentration on the exponential dependence of reciprocal mobility on DNA length
Author(s) -
Rill Randolph L.,
Beheshti Afshin,
Van Winkle David H.
Publication year - 2002
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/1522-2683(200208)23:16<2710::aid-elps2710>3.0.co;2-0
Subject(s) - reptation , agarose , electrophoresis , dna , analytical chemistry (journal) , chemistry , exponential function , gel electrophoresis , electric field , chromatography , physics , polymer , quantum mechanics , biochemistry , mathematics , organic chemistry , mathematical analysis
Electrophoretic mobilities of DNA molecules ranging in length from 200 to 48 502 base pairs (bp) were measured in agarose gels with concentrations T = 0.5% to 1.3% at electric fields from E = 0.71 to 5.0 V/cm. This broad data set determines a range of conditions over which the new interpolation equation ν( L ) = (β+α(1+exp(– L /γ)) –1 can be used to relate mobility to length with high accuracy. Mobility data were fit with χ 2 > 0.999 for all gel concentrations and fields ranging from 2.5 to 5 V/cm, and for lower fields at low gel concentrations. Analyses using so‐called reptation plots (Rousseau, J., Drouin, G., Slater, G. W., Phys. Rev. Lett. 1997, 79 , 1945–1948) indicate that this simple exponential relation is obeyed well when there is a smooth transition from the Ogston sieving regime to the reptation regime with increasing DNA length. Deviations from this equation occur when DNA migration is hindered, apparently by entropic‐trapping, which is favored at low fields and high gel concentrations in the ranges examined.