Naslov
Screening and fundamental length scales in semidilute Na-DNA solutions

Autori
Tomić, Silvia ; Vuletić, Tomislav ; Dolanski Babić, Sanja ; Krča, Sanja ; Ivanković, Dušica ; Griparić, Lorena ; Podgornik, Rudi

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
From Solid State to BioPhysics III / Forro, Laszlo ; Pavuna, Davor - Lausanne : Ecole Polytechnique Federale de Lausanne, 2006

Skup
International Conference From Solid State to BioPhysics III

Mjesto i datum
Cavtat, Hrvatska, 24.06.2006. - 01.07.2006

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Nije recenziran

Ključne riječi
DNA dielectric relaxation; fundamental length scales

Sažetak
The fundamental length scales in semidilute Na-DNA aqueous solutions have been investigated by low-frequency dielectric spectroscopy. The low and the high frequency relaxation modes were studied in detail. The characteristic length scale of the LF process varies with the concentration of DNA as c_{;\textrm{;DNA};};^{;- 0.25}; and is independent of the ionic strength in the low added salt regime. Conversely, it does not vary with the concentration of DNA but depends on the ionic strength of the added salt as $I_s^{;-1};$ in the high added salt regime. These features suggest that the corresponding length scale can be identified as an average size of the Gaussian chain composed of correlation blobs in the low added salt limit, and as the Odijk-Skolnick-Fixman value of the single chain persistence length in the high added salt limit. On the other hand, the characteristic length scale of the HF process can be identified as de Gennes - Pfeuty – Dobrynin correlation length of polyelectrolytes in semidilute solution, since it varies with the concentration of DNA as c_{;\textrm{;DNA};};^{;-0.5};$ and is independent of the ionic strength in the low added salt regime. The behavior of the HF relaxation at low DNA concentrations and in low added salt limit will be also discussed.

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Biologija

POVEZANOST RADA