Ion relaxation plays an important role in a wide range of phenomena involvi
ng the transport of charged biomolecules. ion relaxation is responsible for
reducing sedimentation and diffusion constants, reducing electrophoretic m
obilities, increasing intrinsic viscosities, and, for biomolecules that lac
k a permanent electric dipole moment, provides a mechanism for orienting th
em in an external electric field. Recently, a numerical boundary element me
thod was developed to solve the coupled Navier-Stokes, Poisson, and ion tra
nsport equations for a polyion modeled as a rigid body of arbitrary size, s
hape, and charge distribution. This method has subsequently been used to co
mpute the electrophoretic mobilities and intrinsic viscosities of a number
of model proteins and DNA fragments. The primary purpose of the present wor
k is to examine the effect of ion relaxation on the ion density and fluid v
elocity fields around short DNA fragments (20 and 40 bp). Contour density a
s well as vector field diagrams of the various scalar and vector fields are
presented and discussed at monovalent salt concentrations of 0.03 and 0.11
M. In addition, the net charge current fluxes in the vicinity of the DNA f
ragments at low and high salt concentrations are briefly examined and discu
ssed.