Size dependent separation of high molecular weight double-stranded DNA by means of gel electrophoresis

Lishanskaya, A.I.; Mosevitsky, Mark I.

doi:10.1016/0006-291x(73)90629-3

Cited by 20 publications

(8 citation statements)

References 14 publications

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“…Dependence on Electric Field Strength. The apparent mobilities of some of the larger restriction fragments increased with increasing field strength, as previously noted (Fisher & Dingman, 1971;Lishanskaya & Mosevitsky, 1973). This dependence on electric field strength was observed for fragments larger than 1000 bp in 4.6% gels and for fragments between 300 and 2100 bp in 6.9% gels.…”

supporting

confidence: 80%

Anomalous electrophoresis of deoxyribonucleic acid restriction fragments on polyacrylamide gels

Stellwagen¹

1983

Biochemistry

148

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A detailed study has been made of the polyacrylamide gel electrophoresis of DNA restriction fragments obtained from two plasmids, pBR322 and p82-6B. Variables studied were molecular weight, gel concentration, temperature, and electric field strength. The retardation coefficients of the larger fragments (greater than 800 base pairs) were independent of molecular weight. The retardation coefficients of the smallest fragments (less than or equal to 300 base pairs) were proportional to Mr1/3, and therefore to the mean geometric radii of the fragments. The logarithm of the relative mobility of all fragments was also proportional to Mr1/3. The anomalous migration of certain fragments on polyacrylamide gels was found to be "transportable" into fragments generated by different restriction enzymes. Anomalous migration was enhanced at lower temperatures and disappeared upon increasing the temperature. A fragment which migrated anomalously slowly migrated even more anomalously when dimerized; dimerizing a normally migrating fragment resulted in the normal migration of the dimerized fragment. Anomalously migrating fragments were found to be localized in distinct regions of the pBR322 circle.

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confidence: 80%

Anomalous electrophoresis of deoxyribonucleic acid restriction fragments on polyacrylamide gels

Stellwagen¹

1983

Biochemistry

148

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“…(7), is difficult to reconcile with the observation made here that DNA stretching has considerably more impact than tube orientation on the field dependence of the mobility. This can be seen by analyzing the effect which stretching will have on the detour factor in the different phases of the migration cycle, assuming for the sake of the argument that the tube orientation is not affected.…”

Section: Mobility and Tube Friction In Fluctuating Tubescontrasting

confidence: 58%

Cyclic migration of DNA in gels: DNA stretching and electrophoretic mobility

Åkerman¹

1996

Electrophoresis

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Available data from spectroscopic and microscopy studies of electrophoretic orientation of long DNA (above 40 kbp) in agarose gels is analyzed on the basis of the fact that the migration in constant fields is cyclic in nature. Defining a cycle period as the time between two consecutive compact states, a simple model is used to obtain data on the average time period (< T >) and the step length (< L >) of the migration cycle from spectroscopic measurements of the dynamics of helix orientation and center-of-mass velocity. Furthermore, the degree of orientation is used to analyze tube-orientation and DNA stretching contributions to < L > and < T >. Finally, the average electrophoretic velocity v = < L >/< T > is analyzed in terms of < L > and < T > for different DNA sizes (Lc), field strengths (E), and gel concentrations (A). The main results of the analysis are: (i) the increase and saturation of the electrophoretic mobility with increasing E is mainly governed by < L > via the degree of DNA stretching, (ii) DNA molecules of different sizes migrate with the same velocity because < L > and < T > both increase approximately linearly with Lc, and (iii) migration in a denser gel is slower mainly because < T > increases, while the step length is approximately constant. Assuming the charge Q of DNA is the same as in free solution, these results suggest that the reason the fundamental reptation equation for the electrophoretic mobility mu = (Q/zeta) < (hx/Lt)2 > also applies in the presence of strong fluctuations in the tube length Lt, and end-to-end distance hx, is that the friction coefficient zeta for motion along the tube is lower the more stretched the DNA is.

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“…When electrophoresis is performed in a gel, the effect of particle size and shape on fractionation increases (reviewed in [ 6,7]). Flexibility of particles may also alter their fractionation [8, 91. Materialsusedto form gels include starch, polyacrylamide and either agar or its least charged (see below) subcomponent, agarose (see reviews in .…”

Section: Introductionmentioning

confidence: 99%