Rheological Properties of DNA Molecules in Solution: Molecular Weight and Entanglement Influences

Abstract

Molecular weight, stiffness, temperature, and polymer and ionic concentrations are known to widely influence the viscosity of polymer solutions. Additionally, polymer molecular weight-which is related to its dimensions in solution-is one of its most important characteristics. In this communication, low molecular weight DNA from salmon sperm was purified and then studied in solutions in a wide concentration range (between 0.5 and 1600 mg/mL). The intrinsic viscosity of this low molecular weight DNA sample was firstly determined and the evidence of the overlap concentration was detected around the concentration of 125 mg/mL. The chain characteristics of these short molecules were studied in terms of the influence of their molecular weight on the solution viscosities and on the overlap parameter C DNA [η]. Furthermore, to complete previously reported experimental data, solutions of a large molecular weight DNA from calf-thymus were studied in a high concentration range (up to 40 mg/mL). The rheological behavior is discussed in terms of the generalized master curve obtained from the variation of the specific viscosity at zero shear rate (η sp,0 ) as a function of C DNA [η].

DNA Microviscosity Characterization with Particle Diffusometry for Downstream DNA Detection Applications

“…The viscous behavior of DNA suspensions provides analytical information which can be applied both in fundamental characterization of cellular responses to DNA crowding, characterization of DNA binding properties, , nucleic acid drug interactions, and in translational applications such as designing alternative methods for detecting nucleic acid amplification . To study the viscosity of DNA, characterization is often performed with traditional measurement techniques (capillary viscometers, cone-and-plate). These techniques require large sample volumes (>60 μL) to perform such analyses, and because they are often destructive, the sample can no longer be used in downstream applications.…”

Viscosity of a solution of polyelectrolytes near the rod limit

“…Finally I consider an organic stiff polymer: a low molecular weight DNA from salmon sperm in water with added salt (NaCl) 19 ; the experimental parameters give c L ≪ c 1 , allowing the comparison in the dilute and semidilutes regime. In this case, c s = 0.1 mol l −1 , MM = 15 000 g and A = 0.34 nm, where A here represents the distance between a pair of charges (one for each nucleotide) along the rod.…”

“…On the other hand, biological stiff macromolecules such as DNA fragments, oligonucleotides and short biomolecules are important in nanotechnology studies, due to their contribution to several biological processes such as DNA packing around histones, compaction, gene transcription, gene delivery via small volume carriers for gene therapy, among others. 17–23…”

Fabrication and characterization of melamine formaldehyde fibers with enhanced mechanical properties and high fire resistance by dry spinning

“…When the temperature increases, energy transfer from the environment to the system is enhanced, molecules move more violently, the distances between molecules increase, free volume increases, the intermolecular force decreases, internal friction reduces; thus, the spinning solutions show shear‐thinning on the macroscopic scale 30 . The apparent viscosity of spinning liquids increases with the addition of PVA, owing to the long chain nature of the PVA molecules that cause molecular entanglement 31 . Moreover, it appears that doping nano‐SiO 2 in raw materials reduces the apparent viscosity of the spinning solutions.…”