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McLoughlin, Daragh; O'Brien, Julie L.; McManus, Jennifer J.; Gorelov, Alexander; Dawson, Kenneth A.

doi:10.1023/a:1011182806783

Cited by 29 publications

(24 citation statements)

References 11 publications

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“…2 (lanes 12-15) correspond to complexes prepared with the same final concentration of CTAB but from stock solutions whose concentration was below the surfactant CMC (0.9 mM in this case). This last experiment was performed because it has been suggested [29] that when the surfactant is added in the micellar form the DNA condensation will not be as efficient as when added in the monomer form, so the formed complex could retain some negative charges. However, we observed no assignable differences between the two sets of samples (lanes 5, 7, 9, 11, and 12-15).…”

Section: No Complex-dissolution Due To Dilutionmentioning

confidence: 99%

Electrophoretic properties of complexes between DNA and the cationic surfactant cetyltrimethylammonium bromide

et al. 2005

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Electrophoretic properties of complexes between DNA and the cationic surfactant cetyltrimethylammonium bromideWe use agarose gel electrophoresis to characterize how the monovalent catioinic surfactant cetyltrimethylammonium bromide (CTAB) compacts double-stranded DNA, which is detected as a reduction in electrophoretic DNA velocity. The velocity reaches a plateau at a ratio R = 1.8 of CTAB to DNA-phosphate charges, i.e., above the neutralization point, and the complexes retain a net negative charge at least up to R = 200. Condensation experiments on a mixture of two DNA sizes show that the complexes formed contain only one condensed DNA molecule each. These CTAB-DNA globules were further characterized by time-resolved measurements of their velocity inside the gel, which showed that CTAB does not dissociate during the migration but possibly upon entry into the gel. Using the Ogston-model for electrophoresis of spherical particles, the measured in-gel velocity of the globule is quantitatively consistent with CTAB having two opposite effects, reduction of both the electrophoretic charge and DNA coil size. In the case of CTAB the two effects nearly cancel, which can explain why opposite velocity shifts (globule faster than uncomplexed DNA) have been observed with some catioinic condensation agents. Dissociation of the complexes by addition of anionic surfactants was also studied. The DNA release from the globule was complete at a mixing ratio between anionic and cationic surfactants equal to 1, in agreement with equilibrium studies. Circular DNA retained its supercoiling, and this demonstrates a lack of DNA nicking in the compaction-release cycle which is important in DNA transfection and purification applications. IntroductionComplexation with cationic lipids is one strategy for delivery of DNA to cells. Binding of the lipids leads to compaction of the DNA coils and to a reduction of its surface charge. Both effects are believed to contribute to the facilitated uptake of the nucleic acids through the cellular membrane [1][2][3][4][5]. Methods to monitor size and charge of the complexes are therefore helpful tools in the process of screening protocols for packaging the DNA before in vivo experiments are performed. Commonly a titration series is made where the ratio R between concentration of charges from cationic lipid and DNA-phosphate groups is varied, usually in a range that includes the point R = 1 where the number of added positive and negative charges is equal. It is widely accepted that surfactants display a very strong associative binding with DNA inducing its compaction [6][7][8], aggregation [9], and precipitation [8,10,11]. The associative phase behavior presented by these systems and the absence of redissolution with the addition of an excess of surfactant lead to the assumption that the formed complexes in solution are neutral [8,12].Electrophoresis has been used to study the properties of lipoplexes because the mobility reflects their net charge. Mobilities in free solution have been used [13,14] to q...

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Section: No Complex-dissolution Due To Dilutionmentioning

confidence: 99%

Electrophoretic properties of complexes between DNA and the cationic surfactant cetyltrimethylammonium bromide

et al. 2005

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“…Cationic surfactants, a kind of agent to induce DNA condensation [1], have been used in DNA extraction [2, 3], purification [4], enhancing the fluorescence intensity [5], and have potential uses in gene delivery [6, 7]. Because of its technological and biomedical importance, extensive studies have been carried out to elucidate the mechanism of DNA-surfactant interaction [8, 9].…”

Section: Introductionmentioning

confidence: 99%

Interaction between DNA and Trimethyl-Ammonium Bromides with Different Alkyl Chain Lengths

Cheng

Ran

2014

The Scientific World Journal

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The interaction between λ—DNA and cationic surfactants with varying alkyl chain lengths was investigated. By dynamic light scattering method, the trimethyl-ammonium bromides-DNA complex formation was shown to be dependent on the length of the surfactant's alkyl chain. For surfactants with sufficient long alkyl chain (CTAB, TTAB, DTAB), the compacted particles exist with a size of ~60–110 nm at low surfactant concentrations. In contrast, high concentration of surfactants leads to aggregates with increased sizes. Atomic force microscope scanning also supports the above observation. Zeta potential measurements show that the potential of the particles decreases with the increase of surfactant concentration (CTAB, TTAB, DTAB), which contributes much to the coagulation of the particles. For OTAB, the surfactant with the shortest chain in this study, it cannot fully neutralize the charges of DNA molecules; consequently, the complex is looser than other surfactant-DNA structures.

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“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] There has been considerable interest in characterizing the nature of the fundamental interactions between cationic agents and DNA, and several general approaches have been designed to unravel such interactions. [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37] One of the important driving forces in all of these systems is the long-range electrostatic interaction between molecules of opposite charge.…”

Section: Introductionmentioning

confidence: 99%

Effect of Headgroup on DNA−Cationic Surfactant Interactions

Dasgupta¹,

Das²,

Dias³

et al. 2007

J. Phys. Chem. B

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The interaction behavior of DNA with different types of hydroxylated cationic surfactants has been studied. Attention was directed to how the introduction of hydroxyl substituents at the headgroup of the cationic surfactants affects the compaction of DNA. The DNA-cationic surfactant interaction was investigated at different charge ratios by several methods like UV melting, ethidium bromide exclusion, and gel electrophoresis. Studies show that there is a discrete transition in the DNA chain from extended coils (free chain) to a compact form and that this transition does not depend substantially on the architecture of the headgroup. However, the accessibility of DNA to ethidium bromide is preserved to a significantly larger extent for the more hydrophilic surfactants. This was discussed in terms of surfactant packing. Observations are interpreted to reflect that the surfactants with more substituents have a larger headgroup and therefore form smaller micellar aggregates; these higher curvature aggregates lead to a less efficient, "patch-like" coverage of DNA. The more hydrophilic surfactants also presented a significantly lower cytotoxicity, which is important for biotechnological applications.

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Untitled

Cited by 29 publications

References 11 publications

Electrophoretic properties of complexes between DNA and the cationic surfactant cetyltrimethylammonium bromide

Electrophoretic properties of complexes between DNA and the cationic surfactant cetyltrimethylammonium bromide

Interaction between DNA and Trimethyl-Ammonium Bromides with Different Alkyl Chain Lengths

Effect of Headgroup on DNA−Cationic Surfactant Interactions

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