ࡱ> 463` bjbjss . f$h9   ]]] ] ]]] ̈d] 60f] S ] ]X:1 ] S f $ Screening and fundamental length scales in semidilute Na-DNA solutions S.Tomi1,*, T.Vuleti1, S.Dolanski Babi1,2, S.Kr a3, D.Ivankovi3, L.Gripari4 and R.Podgornik5 1Institut za fiziku, Zagreb, Croatia 2 School of Medicine, University of Zagreb, Croatia 3 Institut Ruer Boakovi, Zagreb, Croatia 4Dept. of Biological Chemistry, UCLA School of Medicine, Los Angeles, USA 5Department of Physics, University of Ljubljana and J.Stefan Institute, Ljubljana, Slovenia and Laboratory of Physical and Structural Biology NICHD, National Institutes of Health, Bethesda, MD  HYPERLINK "mailto:*stomic@ifs.hr" *stomic@ifs.hr, http://real-science.ifs.hr 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  , . R T V Z t  b d T b  ; < = > a b c q r t Ž֓{ hM+\h:>*B*phhM+0J6]jhM+6U]jhM+6U] h:6] h:6 hv86h:h:6 h:6H*hM+56\] hM+6] hv86]hM+hM+H* hM+hM+ hM+H*hM+hP/0 < V X b p < = gd>$a$gd:$a$ 1 hIhM+U hIhIhM+h> 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. ,1h. A!"#$% DyK *stomic@ifs.hryK ,mailto:*stomic@ifs.hr@@@ NormalCJ_HaJmH sH tHDA@D Default Paragraph FontVi@V  Table Normal :V 44 la (k(No List :>@: Title$a$5\mHsH<B@< Body Text$a$mHsH6U@6 Hyperlink >*B*phFV@!F FollowedHyperlink >*B* ph; GH1{<=0000000000000000000000000    =bqX8@0(  B S  ?AW) B,~8C<5DLV3Ed4' FD(G1HJ$I/ JK4 K$jL/MN|W& Ox+PT(QgR/S8-T,ޖU+Vԅ>!!)V`jjw//9     '00\huzz7;;  9*urn:schemas-microsoft-com:office:smarttagsState= *urn:schemas-microsoft-com:office:smarttags PlaceName= *urn:schemas-microsoft-com:office:smarttags PlaceType8*urn:schemas-microsoft-com:office:smarttagsCity9*urn:schemas-microsoft-com:office:smarttagsplaceB*urn:schemas-microsoft-com:office:smarttagscountry-region 8  FHRT^`su|~x6<@FIQhx|FH333 M+I~0v8dV,iwoMt:vY.:Pz>~@