Migration Behavior of Rodlike dsDNA under Electric Field in Homogeneous Polymer Networks

We investigated the migration behavior of rodlike dsDNA in polymer gels and polymer solutions. Tetra-PEG gel, which has a homogeneous network structure, was utilized as a model system, allowing us to systematically tune the polymer volume fraction and molecular weight of network strand. Although we examined the applicability of the existing models, all the models failed to predict the migration behavior. Thus, we proposed a new model based on the Ogston model, which well explained the experimental data of polymer solutions and gels. The polymer volume fraction determined the maximum mobility, while the network strand governed the size sieving effect. From these results, we conclude that the polymer network with lower polymer volume fraction and smaller network strand is better in terms of size separation. The homogeneous polymer network is vital for understanding of particles’ dynamics in polymer network and a promising material for high-performance size separation

Electrophoretic Mobility of Double-Stranded DNA in Polymer Solutions and Gels with Tuned Structures

We report a systematic experimental study on the migration behavior of double-stranded DNA (dsDNA) in polymer networks with precisely controlled network structures. The electrophoretic mobility (μ) appeared to be a power law function of the number of base pairs (<i>n</i>), μ ∼ <i>n</i>^–γ, with 0.36 < γ < 1.46. The variance in γ has been commonly explained using the reptation model with constraint release or using the entropic trapping (ET) model. However, our results indicated that the μ values were expressed as products of a power law function and an exponential function of <i>n</i>, which differs from any of the existing models. The power law function terms corresponded to the existing models, the Rouse model or the reptation model. In polymer gels, we observed a crossover from the Rouse to the reptation model with an increase in <i>n</i>, while the migration behavior in polymer solutions always obeyed the Rouse model. These results revealed that the continuous change in γ was accommodated by the exponential function terms