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Cho YS, Gwak SJ. Novel Sensing Technique for Stem Cells Differentiation Using Dielectric Spectroscopy of Their Proteins. SENSORS (BASEL, SWITZERLAND) 2023; 23:2397. [PMID: 36904601 PMCID: PMC10007102 DOI: 10.3390/s23052397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 02/12/2023] [Accepted: 02/20/2023] [Indexed: 06/18/2023]
Abstract
Dielectric spectroscopy (DS) is the primary technique to observe the dielectric properties of biomaterials. DS extracts complex permittivity spectra from measured frequency responses such as the scattering parameters or impedances of materials over the frequency band of interest. In this study, an open-ended coaxial probe and vector network analyzer were used to characterize the complex permittivity spectra of protein suspensions of human mesenchymal stem cells (hMSCs) and human osteogenic sarcoma (Saos-2) cells in distilled water at frequencies ranging from 10 MHz to 43.5 GHz. The complex permittivity spectra of the protein suspensions of hMSCs and Saos-2 cells revealed two major dielectric dispersions, β and γ, offering three distinctive features for detecting the differentiation of stem cells: the distinctive values in the real and imaginary parts of the complex permittivity spectra as well as the relaxation frequency in the β-dispersion. The protein suspensions were analyzed using a single-shell model, and a dielectrophoresis (DEP) study was performed to determine the relationship between DS and DEP. In immunohistochemistry, antigen-antibody reactions and staining are required to identify the cell type; in contrast, DS eliminates the use of biological processes, while also providing numerical values of the dielectric permittivity of the material-under-test to detect differences. This study suggests that the application of DS can be expanded to detect stem cell differentiation.
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Affiliation(s)
- Young Seek Cho
- Department of Electronic Engineering, Wonkwang University, Iksan 54538, Jeollabuk-do, Republic of Korea
| | - So-Jung Gwak
- Department of Chemical Engineering, Wonkwang University, Iksan 54538, Jeollabuk-do, Republic of Korea
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2
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Penkov NV, Penkova NA. Effective Medium Model Applied to Biopolymer Solutions. APPLIED SPECTROSCOPY 2021; 75:1510-1515. [PMID: 34469187 DOI: 10.1177/00037028211042027] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Studying dielectric properties of heterogeneous systems is challenged by a problem of uncertainty of the ratio between dielectric permittivity of the system and dielectric permittivities of its components. Such ratios can be obtained in some cases using theoretical effective medium models. However, such models have not yet been developed for all the systems possible. Particularly, there is no effective medium model with filamentary inclusions. Such a theoretical model elaborated based on the fundamental principles of electrodynamics of continuous media is suggested in the present work. Any point of a filamentary inclusion with a length that is significantly greater than the thickness can be regarded as being located in a long cylinder-like fragment of the inclusion with stochastic direction of the cylinder axis relative to the external electric field. With this regard, electric field strength and electric induction values were averaged across the entire volume of a two-phase dielectric material. As a result, a model linking the dielectric permittivity of the two-phase system and the dielectric permittivities of both phases was elaborated. The model appears to be highly relevant for studying solutions of biopolymers, such as nucleic acids, fibrillar proteins and protein aggregates, polysaccharides, by means of electrical impedance spectroscopy, dielectric spectroscopy, and terahertz time-domain spectroscopy. The suggested theoretical model was successfully validated on a DNA solution within the terahertz region.
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Affiliation(s)
- Nikita V Penkov
- Institute of Cell Biophysics RAS, Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Pushchino, Russia
| | - Nadezda A Penkova
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Russia
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Penkova NA, Sharapov MG, Penkov NV. Hydration Shells of DNA from the Point of View of Terahertz Time-Domain Spectroscopy. Int J Mol Sci 2021; 22:ijms222011089. [PMID: 34681747 PMCID: PMC8538832 DOI: 10.3390/ijms222011089] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 10/09/2021] [Accepted: 10/10/2021] [Indexed: 11/16/2022] Open
Abstract
Hydration plays a fundamental role in DNA structure and functioning. However, the hydration shell has been studied only up to the scale of 10-20 water molecules per nucleotide. In the current work, hydration shells of DNA were studied in a solution by terahertz time-domain spectroscopy. The THz spectra of three DNA solutions (in water, 40 mm MgCl2 and 150 mM KCl) were transformed using an effective medium model to obtain dielectric permittivities of the water phase of solutions. Then, the parameters of two relaxation bands related to bound and free water molecules, as well as to intermolecular oscillations, were calculated. The hydration shells of DNA differ from undisturbed water by the presence of strongly bound water molecules, a higher number of free molecules and an increased number of hydrogen bonds. The presence of 40 mM MgCl2 in the solution almost does not alter the hydration shell parameters. At the same time, 150 mM KCl significantly attenuates all the found effects of hydration. Different effects of salts on hydration cannot be explained by the difference in ionic strength of solutions, they should be attributed to the specific action of Mg2+ and K+ ions. The obtained results significantly expand the existing knowledge about DNA hydration and demonstrate a high potential for using the THz time-domain spectroscopy method.
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Affiliation(s)
- Nadezda A. Penkova
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, 142290 Pushchino, Russia;
| | - Mars G. Sharapov
- Institute of Cell Biophysics RAS, Federal Research Center “Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences”, 142290 Pushchino, Russia;
| | - Nikita V. Penkov
- Institute of Cell Biophysics RAS, Federal Research Center “Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences”, 142290 Pushchino, Russia;
- Correspondence:
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Sellgren KL, Gregory CW, Klem EJ, Piascik JR, Stoner BR. Microwave disinfection as a treatment for blackwater from dewatered sludge. Gates Open Res 2018. [DOI: 10.12688/gatesopenres.12801.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Background: Fast and efficient on-site treatment of blackwater, rejected from the dewatering process, can decrease the costs associated with disposal of fecal sludge removed from pit latrines by reducing the volume of sludge transported to the disposal site.Methods: In this study, we examine the potential use of low cost consumer microwave units for disinfecting pathogen-rich blackwater. Domestic bench top microwave units were modified to allow flow through and re-circulation of blackwater. Energy, throughput, and disinfection characteristics related to microwaves are studied and compared to conventional thermal heating. A custom flow through stack of 5 microwaves was designed and used to examine the feasibility of single pass, high throughput application.Results and Conclusions: The results show microwave energy does not play a role in the disinfection of blackwater. The benefits of a microwave disinfection system are shown to be high energy efficiency, compact size, and cost efficiency.
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Ghosh R, Banerjee S, Hazra M, Roy S, Bagchi B. Sensitivity of polarization fluctuations to the nature of protein-water interactions: Study of biological water in four different protein-water systems. J Chem Phys 2014; 141:22D531. [DOI: 10.1063/1.4902821] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
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6
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Wang F, Jia G. Consideration of dielectric relaxation of pure DMSO liquid in different temperatures. J Mol Struct 2014. [DOI: 10.1016/j.molstruc.2014.06.066] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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7
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Ermilova E, Bier FF, Hölzel R. Dielectric measurements of aqueous DNA solutions up to 110 GHz. Phys Chem Chem Phys 2014; 16:11256-64. [DOI: 10.1039/c3cp55272a] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Ali MHM, Al-Saad KA, Ali CM. Biophysical studies of the effect of high power ultrasound on the DNA solution. Phys Med 2013; 30:221-7. [PMID: 23850104 DOI: 10.1016/j.ejmp.2013.06.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Revised: 06/19/2013] [Accepted: 06/22/2013] [Indexed: 10/26/2022] Open
Abstract
Stability and molecular size of the DNA double helical structure were studied on an aqueous solution of DNA after exposure to high power doses of continuous wave ultrasound at frequency of 20 kHz. Thermal transition spectrophotometry (UV-melting), constant-field gel electrophoresis (CFGE), differential scanning calorimetry (DSC) and dielectric properties measurements were used to evaluate the ultrasound-induced changes in the DNA double helical structure. The thermal transition spectrophotometry (UV-melting) and differential scanning calorimetry (DSC) results showed that ultrasound power caused loss of DNA double helical structure and the DNA double strands melting temperature decreased as the ultrasound power increased, indicating a decrease in the stability of the double helical structure of DNA. The constant-field gel electrophoresis (CFGE) results showed that the molecular size of the DNA fragments decreased as the ultrasound power increased. The dielectric data in the frequency range from 20 Hz to 100 kHz for the native DNA showed that dispersion at frequency of about 500 Hz resulted from polarization induced by counterions. The decrease in the dielectric increment indicated a decrease in length of DNA molecule after exposure to ultrasound power.
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Affiliation(s)
- Mohamed H M Ali
- Department of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia.
| | - Khalid A Al-Saad
- Department of Chemistry and Earth Sciences, College of Arts and Sciences, Qatar University, Doha, Qatar
| | - Carmen M Ali
- Faculty of Veterinary Science, The University of Sydney, Sydney, NSW 2006, Australia
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Abstract
Miniaturized laboratory-on-chip systems promise rapid, sensitive, and multiplexed detection of biological samples for medical diagnostics, drug discovery, and high-throughput screening. Within miniaturized laboratory-on-chips, static and dynamic droplets of fluids in different immiscible media have been used as individual vessels to perform biochemical reactions and confine the products. Approaches to perform localized heating of these individual subnanoliter droplets can allow for new applications that require parallel, time-, and space-multiplex reactions on a single integrated circuit. Our method positions droplets on an array of individual silicon microwave heaters on chip to precisely control the temperature of droplets-in-air, allowing us to perform biochemical reactions, including DNA melting and detection of single base mismatches. We also demonstrate that ssDNA probe molecules can be placed on heaters in solution, dried, and then rehydrated by ssDNA target molecules in droplets for hybridization and detection. This platform enables many applications in droplets including hybridization of low copy number DNA molecules, lysing of single cells, interrogation of ligand-receptor interactions, and rapid temperature cycling for amplification of DNA molecules.
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Zhadobov M, Augustine R, Sauleau R, Alekseev S, Di Paola A, Le Quément C, Mahamoud YS, Le Dréan Y. Complex permittivity of representative biological solutions in the 2-67 GHz range. Bioelectromagnetics 2011; 33:346-55. [DOI: 10.1002/bem.20713] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2010] [Accepted: 09/19/2011] [Indexed: 01/20/2023]
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11
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Electrical conduction through DNA molecule. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2011; 106:485-97. [PMID: 21396395 DOI: 10.1016/j.pbiomolbio.2011.03.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2010] [Accepted: 03/01/2011] [Indexed: 11/24/2022]
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12
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Regtmeier J, Eichhorn R, Bogunovic L, Ros A, Anselmetti D. Dielectrophoretic Trapping and Polarizability of DNA: The Role of Spatial Conformation. Anal Chem 2010; 82:7141-9. [DOI: 10.1021/ac1005475] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jan Regtmeier
- Experimental Biophysics and Applied Nanoscience, Faculty of Physics, Bielefeld University, Bielefeld, Germany, Nordic Institute for Theoretical Physics (Nordita), Stockholm, Sweden, and Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287
| | - Ralf Eichhorn
- Experimental Biophysics and Applied Nanoscience, Faculty of Physics, Bielefeld University, Bielefeld, Germany, Nordic Institute for Theoretical Physics (Nordita), Stockholm, Sweden, and Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287
| | - Lukas Bogunovic
- Experimental Biophysics and Applied Nanoscience, Faculty of Physics, Bielefeld University, Bielefeld, Germany, Nordic Institute for Theoretical Physics (Nordita), Stockholm, Sweden, and Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287
| | - Alexandra Ros
- Experimental Biophysics and Applied Nanoscience, Faculty of Physics, Bielefeld University, Bielefeld, Germany, Nordic Institute for Theoretical Physics (Nordita), Stockholm, Sweden, and Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287
| | - Dario Anselmetti
- Experimental Biophysics and Applied Nanoscience, Faculty of Physics, Bielefeld University, Bielefeld, Germany, Nordic Institute for Theoretical Physics (Nordita), Stockholm, Sweden, and Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287
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Abstract
The physical properties of DNA are quite important for molecular genetics as well as for its nanotechnological applications. Studying the interactions of alternating current (AC) electric fields with deoxyribonucleic acid (DNA) allows one to draw conclusions about these properties. These interactions are usually investigated in two different ways. In dielectric spectroscopy, a DNA solution is placed in a homogeneous AC field and electronic parameters are measured over several frequency decades in the Hz to GHz range. These electronic data are then interpreted on the basis of physico-chemical models as a result of certain phenomena on the molecular level. In dielectrophoretic studies, a DNA solution is exposed to an inhomogeneous AC field and the spatial response of few or single molecules is monitored by optical or scanning force microscopy. This response can involve translation, elongation and orientation of the molecular strings. In this review, a survey is given of the literature dealing with the dielectric and dielectrophoretic properties of DNA as well as with applications of DNA dielectrophoresis.
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Affiliation(s)
- R Hölzel
- Fraunhofer Institute for Biomedical Engineering, Department of Molecular Bioanalytics and Bioelectronics, Potsdam-Golm, Germany.
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14
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Edwards WF, Young DD, Deiters A. The effect of microwave irradiation on DNA hybridization. Org Biomol Chem 2009; 7:2506-8. [PMID: 19503920 DOI: 10.1039/b903609a] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The effect of microwave irradiation on DNA/DNA hybridization has been studied under controlled power and temperature conditions. It was discovered that microwave irradiation led to the melting of double-stranded deoxyoligonucleotides well below their thermal melting temperature and independent of the length of the deoxyoligonucleotides. These observations indicate a specific interaction of microwaves with DNA, and have important implications in the chemical or enzymatic processing of DNA under microwave heating.
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Affiliation(s)
- Wesleigh F Edwards
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204, USA
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15
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Cerveny S, Alegría A, Colmenero J. Universal features of water dynamics in solutions of hydrophilic polymers, biopolymers, and small glass-forming materials. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2008; 77:031803. [PMID: 18517410 DOI: 10.1103/physreve.77.031803] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2007] [Revised: 10/17/2007] [Indexed: 05/26/2023]
Abstract
A systematic investigation by dielectric spectroscopy of 18 different water-rich mixtures with very different hydrophilic substances shows universal features for the water dynamics. The temperature dependence of the relaxation times exhibits a crossover from non-Arrhenius to Arrhenius behavior at the T(g) range of the mixtures. Furthermore, the temperature dependence of the relaxation times presents a universal behavior both above and below the crossover temperature. We also show that these features suggest that the observed crossover is associated with the emergence of confinement effects.
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Affiliation(s)
- Silvina Cerveny
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018, San Sebastián, Spain
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16
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Previte MJR, Geddes CD. Fluorescence microscopy in a microwave cavity. OPTICS EXPRESS 2007; 15:11640-11649. [PMID: 19547524 DOI: 10.1364/oe.15.011640] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Optical microscopy is a well-established technique that has wide ranging applications for imaging molecular dynamics of biological systems. Typically, these applications rely on external temperature controllers to maintain or change reactions rates of these biological systems. With increasing interest in applying low power microwaves to drive biological and chemical reactions, we have combined optical and microwave based technologies and developed a fluorescence microscope in a microwave cavity. With this instrument, we have found a means to optically image biological systems inside microwave cavities during the application of microwave pulses.
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17
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Tomić S, Babić SD, Vuletić T, Krca S, Ivanković D, Griparić L, Podgornik R. Dielectric relaxation of DNA aqueous solutions. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2007; 75:021905. [PMID: 17358365 DOI: 10.1103/physreve.75.021905] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2006] [Indexed: 05/14/2023]
Abstract
We report on a detailed characterization of complex dielectric response of Na-DNA aqueous solutions by means of low-frequency dielectric spectroscopy (40 Hz-110 MHz). Results reveal two broad relaxation modes of strength 20<Deltaepsilon(LF)<100 and 5<Deltaepsilon(HF)<20, centered at 0.5 kHz<nu(LF)<70 kHz and 0.1 MHz<nu(HF)<15 MHz. The characteristic length scale of the low-frequency (LF) process, 50<L(LF)<750 nm, scales with DNA concentration as c(DNA)(-0.29+/-0.04) and is independent of the ionic strength in the low added salt regime. Conversely, the measured length scale of the LF process does not vary with DNA concentration but depends on the ionic strength of the added salt as I(s)(-1) in the high added salt regime. On the other hand, the characteristic length scale of the high-frequency (HF) process, 3<L(HF)<50 nm, varies with DNA concentration as c(DNA)(-0.5) for intermediate and large DNA concentrations. At low DNA concentrations and in the low added salt limit the characteristic length scale of the HF process scales as c(DNA)(-0.33). We put these results in perspective regarding the integrity of the double stranded form of DNA at low salt conditions as well as regarding the role of different types of counterions in different regimes of dielectric dispersion. We argue that the free DNA counterions are primarily active in the HF relaxation, while the condensed counterions play a role only in the LF relaxation. We also suggest theoretical interpretations for all these length scales in the whole regime of DNA and salt concentrations and discuss their ramifications and limitations.
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Affiliation(s)
- S Tomić
- Institut za fiziku, 10000 Zagreb, Croatia.
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18
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Ermolina I, Milner J, Morgan H. Dielectrophoretic investigation of plant virus particles: Cow Pea Mosaic Virus and Tobacco Mosaic Virus. Electrophoresis 2006; 27:3939-48. [PMID: 17054097 DOI: 10.1002/elps.200500928] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
This paper reports experimental results on the dielectrophoretic (DEP) behaviour on two nonenveloped plant viruses of different geometrical shapes, namely Cow Pea Mosaic Virus (CPMV) and Tobacco Mosaic Virus (TMV). The DEP properties of carboxy-modified latex beads of the same size are also reported. The DEP properties of single particles were obtained from measurement of the frequency at which the DEP force on a particle goes to zero (the crossover frequency). The DEP behaviour of particle ensembles was also measured using image processing. The dielectric properties of the particles were evaluated from the DEP data. The surface conductance was found to be 0.3 nS for CPMV, 0.38 nS for TMV, and 0.52 nS for 27 nm diameter carboxy-latex beads. Data analysis has shown that the optimal condition for separation of TMV and CPMV is a low-conductivity suspending medium - below 1 mS/m.
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Affiliation(s)
- Irina Ermolina
- School of Electronics and Computer Science, University of Southampton, Southampton, UK
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Bonincontro A, Cametti C, Nardiello B, Marchetti S, Onori G. Dielectric behavior of DNA in water–organic co-solvent mixtures. Biophys Chem 2006; 121:7-13. [PMID: 16380204 DOI: 10.1016/j.bpc.2005.12.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2005] [Revised: 12/06/2005] [Accepted: 12/07/2005] [Indexed: 10/25/2022]
Abstract
The radiowave dielectric dispersions of DNA in different water-organic co-solvent mixtures have been measured in the frequency range from 100 kHz to 100 MHz, where the polarization mechanism is generally attributed to the confinement of counterions within some specific lengths, either along tangential or perpendicular to the polyion chain. The dielectric dispersions have been analyzed on the basis of two partially different dielectric models, a continuum counterion fluctuation model proposed by Mandel and a discrete charged site model, proposed by Minakata. The influence of the quality of the solvent on the dielectric parameters has been investigated in water-methanol and water-glycerol mixtures at different composition, by varying the permittivity (m) and the viscosity eta of the solvent phase. The analysis of the dielectric spectra in solvents where electrostatic and hydrodynamic interactions vary with the solvent composition suggests that both the two models are able, in principle, to account for the observed high-frequency dielectric behavior. However, while some certain assumptions are necessary about the polyion structure within the Mandel model, no structural prerequisite is needed within the Minakata model, where the polarization mechanism invoked considers a radial counterion exchange with the outer medium, which is largely independent of the local polyion conformation.
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Affiliation(s)
- A Bonincontro
- Dipartimento di Fisica, Research Center SOFT-INFM-CNR and CNISM Universita' di Roma "La Sapienza" Piazzale A. Moro 5, I-00185- Rome, Italy.
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Sun M, Pejanović S, Mijović J. Dynamics of Deoxyribonucleic Acid Solutions As Studied by Dielectric Relaxation Spectroscopy and Dynamic Mechanical Spectroscopy. Macromolecules 2005. [DOI: 10.1021/ma051596j] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mingyun Sun
- Othmer Department of Chemical and Biological Sciences and Engineering, Polytechnic University, Six MetroTech Center, Brooklyn New York 11201, and Department of Chemical Engineering, Faculty of Technology, University of Belgrade, Belgrade 11000, Serbia & Montenegro
| | - Srdjan Pejanović
- Othmer Department of Chemical and Biological Sciences and Engineering, Polytechnic University, Six MetroTech Center, Brooklyn New York 11201, and Department of Chemical Engineering, Faculty of Technology, University of Belgrade, Belgrade 11000, Serbia & Montenegro
| | - Jovan Mijović
- Othmer Department of Chemical and Biological Sciences and Engineering, Polytechnic University, Six MetroTech Center, Brooklyn New York 11201, and Department of Chemical Engineering, Faculty of Technology, University of Belgrade, Belgrade 11000, Serbia & Montenegro
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21
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Bonincontro A, Marchetti S, Onori G, Rosati A. Interaction cetyltrimethylammonium bromide–DNA investigated by dielectric spectroscopy. Chem Phys 2005. [DOI: 10.1016/j.chemphys.2004.11.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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22
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Vanderstraeten J, Vander Vorst A. Theoretical evaluation of dielectric absorption of microwave energy at the scale of nucleic acids. Bioelectromagnetics 2004; 25:380-9. [PMID: 15197763 DOI: 10.1002/bem.20001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
A theoretical model is proposed for the evaluation of dielectric properties of the cell nucleus between 0.3 and 3 GHz, as a function of its nucleic acids (NA) concentration (CNA). It is based on literature data on dielectric properties of DNA solutions and nucleoplasm. In skeletal muscle cells, the specific absorption rate (SAR) ratio between nucleoplasm and cytoplasm is found to be larger than one for CNA above 30 mg/ml. A nearly linear relationship is found between CNA and this nucleocytoplasmic SAR ratio. Considering the nanoscale of the layer of condensed counterions and bound water molecules at the NA-solution interface, the power absorption per unit volume is evaluated at this precise location. It is found to be between one and two orders of magnitude above that in muscle tissue as a whole. Under realistic microwave (MW) exposure conditions, however, these SAR inhomogeneities do not generate any significant thermal gradient at the scale considered here. Nevertheless, the question arises of a possible biological relevance of nonnegligible and preferential heat production at the location of the cell nucleus and of the NA molecules.
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Hong SM, Park JK, Lee YO. Mechanisms of microwave irradiation involved in the destruction of fecal coliforms from biosolids. WATER RESEARCH 2004; 38:1615-25. [PMID: 15016539 DOI: 10.1016/j.watres.2003.12.011] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2003] [Revised: 11/20/2003] [Accepted: 12/09/2003] [Indexed: 05/22/2023]
Abstract
Microwaves have been found to be effective in destructing pathogens in sewage sludge (biosolids) (75th Annual Water Environment Federation Conference, Chicago, September 29-October 2, 2002; Third World Water Congress, International Water Association, Melbourne, Australia, April 7-12, 2002). Mechanisms and roles of microwaves on fecal coliform destruction were investigated using bacterial viability tests, electron transport system (ETS) and beta-galactosidase activity assays, gel electrophoresis, and genomic deoxyribonucleic acid (DNA) optical density (OD) measurements with fecal coliforms isolated from biosolids. Bacterial viability tests demonstrated cell membrane damage as microwave irradiation intensity and temperature increased. Above 60+/-3 degrees C, viable cells were rarely found when pure fecal coliforms were irradiated with microwaves. ETS and beta-galactosidase activity assays revealed increased activity for externally heated samples due to fecal coliform growth but decreased activity for microwave-irradiated samples as temperature was increased from 20 degrees C to 57 degrees C, indicating other destruction mechanisms besides heating. Between 57 degrees C and 68 degrees C, microwave irradiation led to a more rapid decrease in activity than external heating by convection. Above 68 degrees C, bacterial activity almost ceased for both pretreatments. DNA bands in gel electrophoresis tests and OD of genomic DNA decreased more rapidly for microwave-irradiated samples than for externally heated samples, implying that microwaves disrupted DNA in fecal coliform cells at lower temperatures than external heating. Microwave irradiation of sludge appears to be a viable and economical method of destructing pathogens and generating environmentally safe sludge.
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Affiliation(s)
- Seung M Hong
- Daewoo Environmental Technology Research Center, Soowon, South Korea
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24
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Bonincontro A, Marchetti S, Onori G, Santucci A. Complex formation between DNA and dodecyl-dimethyl-amine-oxide induced by pH. Chem Phys Lett 2003. [DOI: 10.1016/s0009-2614(03)00074-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Smye SW, Chamberlain JM, Fitzgerald AJ, Berry E. The interaction between Terahertz radiation and biological tissue. Phys Med Biol 2001; 46:R101-12. [PMID: 11580188 DOI: 10.1088/0031-9155/46/9/201] [Citation(s) in RCA: 187] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Terahertz (THz) radiation occupies that region of the electromagnetic (EM) spectrum between approximately 0.3 and 20 THz. Recent advances in methods of producing THz radiation have stimulated interest in studying the interaction between radiation and biological molecules and tissue. Given that the photon energies associated with this region of the spectrum are 2.0 x 10(-22) to 1.3 x 10(-20) J, an analysis of the interactions requires an understanding of the permittivity and conductivity of the medium (which describe the bulk motions of the molecules) and the possible transitions between the molecular energy levels. This paper reviews current understanding of the interactions between THz radiation and biological molecules, cells and tissues. At frequencies below approximately 6 THz. the interaction may be understood as a classical EM wave interaction (using the parameters of permittivity and conductivity), whereas at higher frequencies. transitions between different molecular vibrational and rotational energy levels become increasingly important and are more readily understood using a quantum-mechanical framework. The latter is of particular interest in using THz to probe transitions between different vibrational modes of deoxyribonucleic acid. Much additional experimental work is required in order to fully understand the interactions between THz radiation and biological molecules and tissue.
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Affiliation(s)
- S W Smye
- Department of Medical Physics & Engineering, Leeds Teaching Hospitals NHS Trust, UK
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26
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Bakewell DJ, Ermolina I, Morgan H, Milner J, Feldman Y. Dielectric relaxation measurements of 12 kbp plasmid DNA. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1493:151-8. [PMID: 10978517 DOI: 10.1016/s0167-4781(00)00176-7] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The dielectric properties of 12 kbp plasmid DNA have been measured as a function of temperature in the range 5 degrees C to 40 degrees C. Time domain reflectometry was used to obtain dielectric data over the frequency range from 200 kHz to 3 GHz. Values of the frequency dependent polarisability per DNA macromolecule have been determined from the measurements. Possible mechanisms that could account for the dielectric dispersion are also discussed, in particular the counterion fluctuation model of Manning-Mandel-Oosawa.
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Affiliation(s)
- D J Bakewell
- Bioelectronics Research Centre, Department of Electronics and Electrical Engineering, University of Glasgow, Glasgow G12 8LT, UK
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27
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Nandi N, Bhattacharyya K, Bagchi B. Dielectric relaxation and solvation dynamics of water in complex chemical and biological systems. Chem Rev 2000; 100:2013-46. [PMID: 11749282 DOI: 10.1021/cr980127v] [Citation(s) in RCA: 688] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- N Nandi
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore, 560012, India
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28
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Hartwich G, Caruana DJ, de Lumley-Woodyear T, Wu Y, Campbell CN, Heller A. Electrochemical Study of Electron Transport through Thin DNA Films. J Am Chem Soc 1999. [DOI: 10.1021/ja9920664] [Citation(s) in RCA: 118] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Gerhard Hartwich
- Contribution from the Department of Chemical Engineering and the Texas Materials Institute, The University of Texas at Austin, Austin, Texas 78712-1062
| | - Daren J. Caruana
- Contribution from the Department of Chemical Engineering and the Texas Materials Institute, The University of Texas at Austin, Austin, Texas 78712-1062
| | - Thierry de Lumley-Woodyear
- Contribution from the Department of Chemical Engineering and the Texas Materials Institute, The University of Texas at Austin, Austin, Texas 78712-1062
| | - Yubin Wu
- Contribution from the Department of Chemical Engineering and the Texas Materials Institute, The University of Texas at Austin, Austin, Texas 78712-1062
| | - Charles N. Campbell
- Contribution from the Department of Chemical Engineering and the Texas Materials Institute, The University of Texas at Austin, Austin, Texas 78712-1062
| | - Adam Heller
- Contribution from the Department of Chemical Engineering and the Texas Materials Institute, The University of Texas at Austin, Austin, Texas 78712-1062
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29
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Bonincontro A, D'Archivi AA, Galantini L, Giglio E, Punzo F. On the Micellar Aggregates of Alkali Metal Salts of Deoxycholic Acid. J Phys Chem B 1999. [DOI: 10.1021/jp990278h] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Adalberto Bonincontro
- INFM, Dipartimento di Fisica, Università di Roma “La Sapienza”, P.le A. Moro 5, 00185 Roma, Italy
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30
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Abstract
In this article, measurements are reported on ice and frozen DNA solutions between 100 Hz-10 MHz. Pure ice is shown to exhibit single relaxation behaviour, which confirms previous work taken over a more restricted frequency range. The frozen DNA solution displays double-dispersion behaviour. One dispersion centred around 3 kHz is due to a defect mechanism while the other, centred around 2 MHz, may be attributed to counterion flow through the water immediately adjacent to the DNA molecule.
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Affiliation(s)
- C Gabriel
- Microwave Consultants Ltd., London, UK
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31
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Lee RS, Bone S. Dielectric studies of chain melting and denaturation in native DNA. BIOCHIMICA ET BIOPHYSICA ACTA 1998; 1397:316-24. [PMID: 9582445 DOI: 10.1016/s0167-4781(98)00024-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Dielectric methods, based on time domain reflectometry (TDR), have been employed to characterise DNA chain melting and denaturation. A dielectric dispersion has been identified, centred in the low megahertz region, which has been attributed to the fluctuation of counterions along short segments of the DNA chain. Chain melting studies have shown that the magnitude of this dispersion is dependent not only on the relative proportions of single to double stranded DNA but also on the intermolecular interactions between the DNA chains.
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Affiliation(s)
- R S Lee
- Institute of Molecular and Biomolecular Electronics, University of Wales, Dean Street, Bangor, Gwynedd, LL57 1UT, UK.
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32
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Affiliation(s)
- Nilashis Nandi
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore, India 560012
| | - Biman Bagchi
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore, India 560012
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33
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Bonincontro A, Briganti G, D'Archivio AA, Galantini L, Giglio E. Structural Study of the Micellar Aggregates of Sodium Taurodeoxycholate. J Phys Chem B 1997. [DOI: 10.1021/jp964004v] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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34
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Laitinen E, Salonen K, Harju T. Solvation dynamics study of 4‐amino‐N‐methyl‐phthalimide in n‐alcohol solutions. J Chem Phys 1996. [DOI: 10.1063/1.471279] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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35
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Bone S, Lee RS, Hodgson CE. Dielectric studies of intermolecular interactions in native DNA. BIOCHIMICA ET BIOPHYSICA ACTA 1996; 1306:93-7. [PMID: 8611629 DOI: 10.1016/0167-4781(95)00232-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The concentration dependence of the high frequency dielectric dispersion exhibited by solutions of DNA and the sensitivity of this to the ionic strength of the solution are described. Dielectric data obtained are consistent with a model involving the fluctuation of counterions along short segments of the DNA chain. The concentration and ion strength dependencies are discussed in terms of intermolecular interactions which are considered responsible for the existence of structure in DNA solutions.
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Affiliation(s)
- S Bone
- Institute of Molecular and Biomolecular Electronics, University of Wales, Bangor, Gwynedd, UK
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36
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Schönknecht T, Pörschke D. Electrooptical analysis of α-chymotrypsin at physiological salt concentration. Biophys Chem 1996; 58:21-8. [PMID: 17023346 DOI: 10.1016/0301-4622(95)00082-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/1995] [Revised: 05/10/1995] [Accepted: 05/15/1995] [Indexed: 11/28/2022]
Abstract
The electric dichroism of alpha-chymotrypsin has been measured in a buffer containing 0.1 M Na(+), 10 mM Mg(2+) and 25 mM Tris-cacodylate pH 7.2. The reduced dichroism as a function of the electric field strength can be represented by the orientation function for permanent dipoles and is not consistent with the orientation function for induced dipoles. After correction for the internal directing field, the dipole moment is 1.1 x 10(-27) Cm (+/- 10%), corresponding to 340 D, at 20 degrees C. The assignment of the permanent dipole moment is confirmed by the shape of the dichroism rise curves, which require two exponentials with amplitudes of opposite sign for fitting. The dichroism decay time constants measured in the range of temperatures between 2 and 30 degrees C indicate a temperature induced change of the structure, which is equivalent to an increase of the hydrodynamic radius from r = 26.6 A at 2 degrees C to 28.5 A at 30 degrees C. Our results demonstrate that electrooptical investigations of proteins with a high time resolution can be extended to physiological salt concentrations without serious problems by use of appropriate instruments.
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Affiliation(s)
- T Schönknecht
- Max Planck Institut für Biophysikalische Chemie D-37077 Göttingen, Germany
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37
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Bone S, Small CA. Dielectric studies of ion fluctuation and chain bending in native DNA. BIOCHIMICA ET BIOPHYSICA ACTA 1995; 1260:85-93. [PMID: 7999800 DOI: 10.1016/0167-4781(94)00181-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The high-frequency dielectric dispersion exhibited by solutions of native DNA is characterised as a function of electrolyte concentration, counterion type, temperature and pH. The data are interpreted in terms of counterion fluctuation along short segments (subunits) of the DNA chain. From calculation of the subunit length from dielectric relaxation time and increment, information is derived regarding the static and dynamic bending of the DNA chain. Activation enthalpies for the ion fluctuation process are obtained from temperature-dependent dielectric data.
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Affiliation(s)
- S Bone
- Institute of Molecular and Biomolecular Electronics, University of Wales, Bangor, Gwynedd, UK
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38
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Bernhardt JH. Non-ionizing radiation safety: radiofrequency radiation, electric and magnetic fields. Phys Med Biol 1992; 37:807-44. [PMID: 1589456 DOI: 10.1088/0031-9155/37/4/001] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- J H Bernhardt
- Institut for Radiation Hygiene, Federal Office of Radiation Protection, Neuherberg, Federal Republic of Germany
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39
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Saif B, Mohr RK, Montrose CJ, Litovitz TA. On the mechanism of dielectric relaxation in aqueous DNA solutions. Biopolymers 1991; 31:1171-80. [PMID: 1790296 DOI: 10.1002/bip.360311005] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The complex dielectric response of calf thymus DNA in aqueous saline solutions has been measured from 1 MHz to 1 GHz. The results are presented in terms of the relaxation of the incremental contributions to the permittivity and conductivity from the condensed counterions surrounding the DNA molecules. Measurements of the low-frequency conductivity of the samples also lends support to the condensed counterion interpretation.
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Affiliation(s)
- B Saif
- Vitreous State Laboratory, Catholic University of America, Washington, DC 20064
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40
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Pedone F, Bonincontro A. Temperature dependence of DNA dielectric dispersion at radiofrequency. BIOCHIMICA ET BIOPHYSICA ACTA 1991; 1073:580-4. [PMID: 2015282 DOI: 10.1016/0304-4165(91)90233-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We have studied the dielectric behavior of DNA aqueous solutions at various ionic strengths and in the presence of the specific DNA ligand ethidium bromide, in the frequency range 1 MHz-1 GHz, at different temperatures ranging from 5 to 40 degrees C. The activation enthalpies of the dielectric relaxations studied were obtained by Arrhenius plots of In(tau T)-1 vs. T-1. The results are consistent with a counterion fluctuation model as previously developed by Mandel and colleagues.
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Affiliation(s)
- F Pedone
- Dipartimento di Genetica e Biologia Molecolare, Università di Roma, La Sapienza, Italy
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41
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Eisenhaber F, Tumanyan VG, Eisenmenger F, Gunia W. Hydration of B-DNA: comparison between the water network around poly(dG).poly(dC) and poly(dG-dC).poly(dG-dC) on the basis of Monte Carlo computations. Biopolymers 1989; 28:741-61. [PMID: 2706312 DOI: 10.1002/bip.360280305] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
A computational method is elaborated for studying the water environment around regular polynucleotide duplexes; it allows rigorous structural information on the hydration shell of DNA to be obtained. The crucial aspect of this Monte Carlo simulation is the use of periodical boundary conditions. The output data consists of local maxima of water density in the space near the DNA molecule and the properties of one- and two-membered water bridges as function of pairs of polar groups of DNA. In the present paper the results for poly(dG).poly(dC) and poly(dG-dC).poly(dG-dC) are presented. The differences in their hydration shells are of a purely structural nature and are caused by the symmetry of the polar groups of the polymers under study, the symmetry being reflected by the hydration shell. The homopolymer duplex hydration shell mirrors the mononucleotide repeat. The water molecules contacting the polynucleotide in the minor groove are located nearly in the plane midway between the planes of successive base pairs. One water molecule per base pair forms a water bridge facing two polar groups of bases from adjacent base pairs and on different strands making a "spine"-like structure. In contrast, the major groove hydration is stabilized exclusively by two-membered water bridges; the water molecules deepest in the groove are concentrated near the plane of the corresponding base pair. The alternating polymer is characterized by a marked dyad symmetry of the hydration shell corresponding to the axis between two successive base pairs. The minor groove hydration of the dCpdG step resembles the characteristic features of the homopolymer, but the bridge between the O2 oxygens of the other base-stacking type is formed by two water molecules. The major groove hydration is characterized by high probability of one-membered water bridges and by localization of a water molecule on the dyad axis of the dGpdC step. The found structural elements are discussed as reasonable invariants of a dynamic hydration shell.
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42
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Gabriel C, Grant EH, Tata R, Brown PR, Gestblom B, Noreland E. Dielectric behavior of aqueous solutions of plasmid DNA at microwave frequencies. Biophys J 1989; 55:29-34. [PMID: 2649162 PMCID: PMC1330440 DOI: 10.1016/s0006-3495(89)82777-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The relative permittivity and dielectric loss of aqueous solutions of plasmid (pUC8.c1 and pUC8.c2) DNA have been measured at 20 degrees C over the frequency range 100 MHz-10 GHz. The solutions had a concentration of 0.1% DNA, and were studied both in the relaxed and the supercoiled form. The dielectric measurements were made using a variety of techniques including frequency domain and time domain methods of operation. No evidence of any resonance absorption, nor of any other kind of enhanced absorption, was observed.
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Affiliation(s)
- C Gabriel
- Department of Physics and Biochemistry, King's College, London, United Kingdom
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43
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Kashpur VA, Glibitsky GM, Krasnitskaya AA, Veretelnik YV. Does DNA absorb microwave energy? Biopolymers 1987; 26:1965-70. [PMID: 3318946 DOI: 10.1002/bip.360261110] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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44
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Abstract
An attempt was made to confirm previous reports of resonant-like dielectric absorption of plasmid DNA in aqueous solutions at 1-10 GHz. The dielectric properties of the sample were measured using an automatic network analyzer with two different techniques. One technique used an open-ended coaxial probe immersed in the sample; the other employed a coaxial transmission line. No resonances were observed that could be attributed to the sample; however, resonance-type artifacts were prominent in the probe measurements. The coaxial line technique appears to be less susceptible to such artifacts. We note two important sources of error in the calibration of the automatic network analyzer using the probe technique.
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Affiliation(s)
- K R Foster
- Department of Bioengineering, University of Pennsylvania, Philadelphia 19104
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45
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Mashimo S, Umehara T, Ota T, Kuwabara S, Shinyashiki N, Yagihara S. Evaluation of complex permittivity of aqueous solution by time domain reflectometry. J Mol Liq 1987. [DOI: 10.1016/0167-7322(87)80036-3] [Citation(s) in RCA: 64] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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46
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Pethig R, Kell DB. The passive electrical properties of biological systems: their significance in physiology, biophysics and biotechnology. Phys Med Biol 1987; 32:933-70. [PMID: 3306721 DOI: 10.1088/0031-9155/32/8/001] [Citation(s) in RCA: 612] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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47
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Urry DW, Henze R, Redington P, Long MM, Prasad KU. Temperature dependence of dielectric relaxations in alpha-elastin coacervate: evidence for a peptide librational mode. Biochem Biophys Res Commun 1985; 128:1000-6. [PMID: 3994707 DOI: 10.1016/0006-291x(85)90146-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The dielectric permittivity of alpha-elastin coacervate is reported over the frequency range of 1 MHz to 1000 MHz and the temperature dependence from 6.8 degrees C to 70 degrees C is also reported. A temperature-dependent simple Debye-type relaxation is observed with a correlation time of 8 nsec (40 degrees C) which is similar to that of the polypentapeptide of elastin (i.e. 7 nsec at 40 degrees C) where the band has been assigned to a peptide librational mode. By analogy this allows for the first assignment of a peptide librational mode in a naturally occurring polypeptide or protein. The strong spectrally localized band indicates a regularity of structure. The low temperature dependence of the correlation time, giving a 1.7 kcal/mole enthalpy of activation, is consistent with torsional motions associated with a peptide librational mode.
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48
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Protein elasticity based on conformations of sequential polypeptides: The biological elastic fiber. ACTA ACUST UNITED AC 1984. [DOI: 10.1007/bf01025061] [Citation(s) in RCA: 95] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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