2023/06/26 by Manoel Manghi, Audrey Denis, Manghi, Manoel +7
Biochemistry, Genetics and Molecular Biology · Chemistry · Environmental Science · #Biological Physics (physics.bio-ph) #DNA and Nucleic Acid Chemistry #Electrostatics and Colloid Interactions #FOS: Physical sciences #Pharmaceutical and Antibiotic Environmental Impacts #Soft Condensed Matter (cond-mat.soft)
paper · pdf · doi:10.48550/arxiv.2306.14758
openalex publication_date 2023/06/26 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Finding a theoretical formula for the persistence length of polyelectrolytes for the whole experimental range of salt concentration is a long standing challenge. Using the Tethered Particle Motion technique, the double-stranded DNA persistence length is measured for four monovalent and divalent salts on a three-decade concentration range. The formula proposed by Trizac and Shen [EPL, 116 18007 (2016)] and extended to divalent ions fits the data. This formula mixes the high salt limit solution of the Poisson-Boltzmann equation together with the DNA charge renormalisation. Magnesium ions induce a fitted DNA radius smaller than the geometrical one, consistent with a site-specific binding.