https://doi.org/10.1007/s100510050337
Melting of columnar hexagonal DNA liquid crystals
Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University,
P.O. Box 9502, 2300 RA Leiden, The Netherlands
Corresponding author: a maarel_j@rulgca.leidenuniv.nl
Received:
17
November
1997
Revised:
21
January
1998
Accepted:
25
February
1998
Published online: 15 June 1998
The persistence length DNA hexagonal-cholesteric phase transition upon dilution
and/or increase in solvent ionic strength is investigated with polarized light microscopy. The ionic
strength dependence of the transition follows Lindemann criterion 
, i.e., the
hexagonal lattice melts when the root-mean-square fluctuations in transverse order exceed 10%
of the interaxial spacing. The spacings are derived from density and the fluctuations are estimated
with a theory of undulation enhanced electrostatic interactions. Additional support for this theory
is given by the DNA equation of state and anisotropic neutron radiation scattering from
magnetically aligned cholesteric samples just below the phase transition.
PACS: 64.70.-p – Specific phase transition / 61.25.-f – Studies of specific liquid structures / 87.15.-v – Molecular biophysics
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 1998
