  We present a mean-field dynamical theory for single semiflexible polymers
which can precisely capture, without fitting parameters, recent fluorescence
correlation spectroscopy results on single monomer kinetics of DNA strands in
solution. Our approach works globally, covering three decades of strand length
and five decades of time: it includes the complex cross-overs occurring between
stiffness-dominated and flexible bending modes, along with larger-scale
rotational and center-of-mass motion. The accuracy of the theory stems in part
from long-range hydrodynamic coupling between the monomers, which makes a
mean-field description more realistic. Its validity extends even to short,
stiff fragments, where we also test the theory through Brownian hydrodynamics
simulations.
