Short-fragment Na-DNA dilute aqueous solutions: fundamental length scales and screening
| Autor: | Tomic, S., Babic, S. Dolanski, Ivek, T., Vuletic, T., Krca, S., Livolant, F., Podgornik, R. |
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| Rok vydání: | 2008 |
| Předmět: | |
| Zdroj: | Europhys. Lett. 81, 68003 (2008) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1209/0295-5075/81/68003 |
| Popis: | Dielectric spectroscopy is used to investigate fundamental length scales of 146 bp short-fragment (nucleosomal) dilute Na-DNA solutions. Two relaxation modes are detected: the high- and the low-frequency mode. Dependence of the corresponding length scales on the DNA and on the (uni-valent) salt concentration is studied in detail, being different from the case of long, genomic DNA, investigated before. In low added salt regime, the length scale of the high-frequency mode scales as the average separation between DNAs, though it is smaller in absolute magnitude, whereas the length scale of the low-frequency mode is equal to the contour length of DNA. These fundamental length scales in low added salt regime do not depend on whether DNA is in a double stranded or single stranded form. On the other hand, with increasing added salt, the characteristic length scale of low-frequency mode diminishes at low DNA concentrations probably due to dynamical formation of denaturation bubbles and/or fraying in the vicinity of DNA denaturation threshold. Comment: Accepted for publication in Europhysics Letters. 5 pages, 4 figures |
| Databáze: | arXiv |
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