Scaling theory of DNA confined in nanochannels and nanoslits

TL;DR

This paper develops a scaling theory for long DNA molecules confined in nanochannels and nanoslits, revealing multiple regimes and complex chain statistics influenced by confinement-induced effects.

Contribution

It introduces a comprehensive scaling analysis accounting for various confinement regimes and the distinct effects in nanochannels versus nanoslits, advancing understanding of DNA behavior.

Findings

Identification of multiple confinement regimes between de Gennes and Odijk limits

Derivation of nontrivial power laws for DNA extension in intermediate regimes

Highlighting differences in DNA confinement effects between nanochannels and nanoslits

Abstract

A scaling analysis is presented of the statistics of long DNA confined in nanochannels and nanoslits. It is argued that there are several regimes in between the de Gennes and Odijk limits introduced long ago. The DNA chain folds back on itself giving rise to a global persistence length which may be very large owing to entropic deflection. Moreover, there is an orientational excluded-volume effect between the DNA segments imposed solely by the nanoconfinement. These two effects cause the chain statistics to be intricate leading to nontrivial power laws for the chain extension in the intermediate regimes. It is stressed that DNA confinement within nanochannels differs from that in nanoslits because the respective orientational excluded-volume effects are not the same.