Rheology of semi-dilute solutions of calf-thymus DNA

Bandyopadhyay, Ranjini; Sood, A. K.

doi:10.1007/s12043-002-0025-4

Cited by 17 publications

(17 citation statements)

References 25 publications

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“…The data from Mason et al show a decrease of the absolute value of η from 40 Pas at 0.02 Hz to 1.3 Pas at 3.8 Hz, which is a reduction by a factor of 30 over two orders of magnitude of frequency. A similar behavior has been observed by Bandyopadhyay and Sood 27 . The frequency of the cantilever is around 12.6 kHz.…”

Section: Long Dna Strandssupporting

confidence: 88%

A micro-liter viscosity and density sensor for the rheological characterization of DNA solutions in the kilo-hertz range

2013

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When measuring the properties of fluids from biological sources, sample volumes in the micro-liter range are often desired as higher volumes may not be available or are very expensive. Miniaturized viscosity and density sensors based on a vibrating cantilever fulfill this requirement. In this paper, the possibility of measuring viscosity and density of DNA solutions at the same time using such a sensor is shown. The sensor requires a sample volume of 10 μl. By doing a titration of a solution containing 110 bp long strands of DNA in the diluted, Newtonian regime, the intrinsic viscosity can be determined to be 0.047 ml mg(-1) using the cantilever sensor. The cantilever is also tested with solutions of 10 kbp long strands with concentrations in the semi-dilute, non-Newtonian regime. The comparably small change in resonance frequency and damping observed using these solutions at 12.5 kHz is attributed to shear thinning, which is expected when extrapolating results from other groups.

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Section: Long Dna Strandssupporting

confidence: 88%

A micro-liter viscosity and density sensor for the rheological characterization of DNA solutions in the kilo-hertz range

2013

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“…However, we have observed a plateau region existing beyond ~ 10 2 Hz, but further resolution in this region is limited by amplifier bandwidth. This observation compares well with the reported value in the literature (Mason et al 1998;Bandopadhyay and Sood 2002) for macroscopic rheological measurements.…”

Section: Measurement Of Shear Modulus Of Calf Thymus Dnasupporting

confidence: 92%

Microrheology of concentrated DNA solutions using optical tweezers

Rajkumar

Ali

2008

Bull Mater Sci

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Semiflexible biopolymers play a vital role in shaping cellular structure and rigidity. In this work, we report the determination of microrheological properties of concentrated, double-stranded calf thymus DNA (CT-DNA) solutions using passive, laser-scattering based particle-tracking methodology. From power spectral analysis, we obtain dynamic shear moduli of the polymer solutions stretching over three decades of frequency (10 0 -10 3 Hz) and over concentration ranges spanning from very dilute to concentrated regime. We also study the effects of altered ionic strength and denaturation on the shear modulus. Our results indicate that (CT-DNA) exhibits predominantly elastic behaviour in the concentration range we probed. From the measurements of the plateau shear modulus, G p , we conclude that DNA generally behaves like a semiflexible polymer in a good solvent even at low ionic strength. We have thus demonstrated application of passive microrheological method using optical tweezers to DNA solutions. Further extensions of the technique and its applications are discussed.

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“…The DNA molecule behaves as a semiflexible polymer in semidilute aqueous solution (13,14). Semidilute solutions of DNA are approximately two orders of magnitude higher in viscosity than levan solutions of the same concentration (15,16). It has been suggested that in binary fluid mixtures of widely different viscosities, phase separation processes may occur near a critical point.…”

Section: Introductionmentioning

confidence: 99%

Viscoelastic Properties of Levan-DNA Mixtures Important in Microbial Biofilm Formation as Determined by Micro- and Macrorheology

Stojković

Sretenovic

Dogša

et al. 2015

Biophysical Journal

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We studied the viscoelastic properties of homogeneous and inhomogeneous levan-DNA mixtures using optical tweezers and a rotational rheometer. Levan and DNA are important components of the extracellular matrix of bacterial biofilms. Their viscoelastic properties influence the mechanical as well as molecular-transport properties of biofilm. Both macro- and microrheology measurements in homogeneous levan-DNA mixtures revealed pseudoplastic behavior. When the concentration of DNA reached a critical value, levan started to aggregate, forming clusters of a few microns in size. Microrheology using optical tweezers enabled us to measure local viscoelastic properties within the clusters as well as in the DNA phase surrounding the levan aggregates. In phase-separated levan-DNA mixtures, the results of macro- and microrheology differed significantly. The local viscosity and elasticity of levan increased, whereas the local viscosity of DNA decreased. On the other hand, the results of bulk viscosity measurements suggest that levan clusters do not interact strongly with DNA. Upon treatment with DNase, levan aggregates dispersed. These results demonstrate the advantages of microrheological measurements compared to bulk viscoelastic measurements when the materials under investigation are complex and inhomogeneous, as is often the case in biological samples.

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Rheology of semi-dilute solutions of calf-thymus DNA

Cited by 17 publications

References 25 publications

A micro-liter viscosity and density sensor for the rheological characterization of DNA solutions in the kilo-hertz range

A micro-liter viscosity and density sensor for the rheological characterization of DNA solutions in the kilo-hertz range

Microrheology of concentrated DNA solutions using optical tweezers

Viscoelastic Properties of Levan-DNA Mixtures Important in Microbial Biofilm Formation as Determined by Micro- and Macrorheology

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