# Rotation-induced macromolecular spooling of DNA

## TL;DR

This paper demonstrates that rotation-induced spooling around a microwire can order long DNA strands, offering a new method to handle genomic-length DNA for sequencing and mapping, overcoming previous limitations.

## Contribution

The study introduces a novel rotation-based technique to deterministically spool and order long DNA molecules, enabling improved genomic analysis.

## Key findings

- DNA elongates under shear flow near a rotating microwire
- Tethered DNA can be fully stretched and spooled by increasing rotation rate
- Method allows handling of long DNA strands, surpassing current technologies

## Abstract

Genetic information is stored in a linear sequence of base-pairs; however, thermal fluctuations and complex DNA conformations such as folds and loops make it challenging to order genomic material for in vitro analysis. In this work, we discover that rotation-induced macromolecular spooling of DNA around a rotating microwire can monotonically order genomic bases, overcoming this challenge. We use single-molecule fluorescence microscopy to directly visualize long DNA strands deforming and elongating in shear flow near a rotating microwire, in agreement with numerical simulations. While untethered DNA is observed to elongate substantially, in agreement with our theory and numerical simulations, strong extension of DNA becomes possible by introducing tethering. For the case of tethered polymers, we show that increasing the rotation rate can deterministically spool a substantial portion of the chain into a fully stretched, single-file conformation. When applied to DNA, the fraction of genetic information sequentially ordered on the microwire surface will increase with the contour length, despite the increased entropy. This ability to handle long strands of DNA is in contrast to modern DNA sample preparation technologies for sequencing and mapping, which are typically restricted to comparatively short strands resulting in challenges in reconstructing the genome. Thus, in addition to discovering new rotation-induced macromolecular dynamics, this work inspires new approaches to handling genomic-length DNA strands.