Differential stability of DNA based on salt concentration

TL;DR

This paper investigates how salt concentration affects DNA stability, showing that DNA is stable within a certain range but becomes unstable at higher salt levels, supported by a statistical model and experimental comparison.

Contribution

It introduces a statistical model to analyze DNA stability across various salt concentrations, explaining the transition from stability to instability.

Findings

DNA stability increases with salt concentration up to a point

Beyond a critical salt level, DNA becomes unstable

Model results closely match experimental data

Abstract

Intracellular positive ions neutralise negative charges on the phosphates of a DNA strand conferring greater strength on the hydrogen bonds that connect complementary strands into a double helix and so confer enhanced stability. Beyond a certain value of salt concentration, the DNA molecule displays a unstable nature {\it in vivo} as well as {\it in vitro}. We consider a wide range of salt concentrations and study the stability of the DNA double helix using a statistical model. Through numerical calculations we attempt to explain the different behaviour exhibited by DNA molecules in this range. We compare our results with experimental data and find a close agreement.