Short-fragment Na-DNA dilute aqueous solutions: Fundamental length scales and screening S. Tomić, S. Dolanski Babić, T. Ivek, T. Vuletić, S. Krča, F. Livolant and R. Podgornik EPL, 81 6 (2008) 68003 Published online: 25 February 2008 DOI: 10.1209/0295-5075/81/68003