Inhomogeneous Reptation of Polymers

TL;DR

This paper investigates the inhomogeneous reptation dynamics of long polymers under localized forces, exploring how force position affects drift velocity and proposing a novel gel magnetophoresis method for size separation.

Contribution

It introduces the concept of inhomogeneous reptation with localized forces and demonstrates the feasibility of size separation of polymers via random-position magnetic beading.

Findings

Drift velocity depends on force application point and polymer length.

A regime exists where size-based separation of polymers is achievable.

Potential application in gel magnetophoresis for long polymers.

Abstract

We study the motion of long polymers (eg DNA) in a gel under the influence of an external force acting locally on small segments of the polymer. In particular, we examine the dependence of the drift velocity on the position where the force acts and the length of the polymer. As an application, we discuss the possibility of gel magnetophoresis - the size-separation of long polymers by the attachment of a magnetic bead at an arbitrary position along the length of the polymer. We show that there is a regime where the separation of such polymers with this `random-position beading' is possible.