ISSN:
1435-1536
Keywords:
Single duplex DNA
;
cationic surfactant
;
fluorescence microscopy
;
coil-globule transition
;
sphere-rod transition of micelles
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract The effect of low-molecular salt, sodium bromide (NaBr), on the conformational behavior of T4DNA globules, compacted with cetyltrimethylammonium bromide (CTAB), was studied in aqueous buffer solution. The conformational dynamics of individual single duplex T4DNA molecules was visualized directly with the use of fluorescence microscopy (FM), whereas viscometry was used for monitoring of the surfactant structure in the aqueous media. We have found that DNA globules, compacted with CTAB, are unfolded into the elongated coil state with the increase of NaBr concentration, exhibiting the character of a discrete first-order phase transition. It is indicated that, accompanied with the increase of NaBr concentration, the unfolding transition is induced simultaneously with the sphere-rod transition of surfactant micelles. These results clearly indicate the cooperative effect between two different types of transitions.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01189522
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