The dynamical behavior of deoxyguanosine 5-monophosphate in the pre-transitional region of the 1-Ch phase transition was investigated by dynamic light scattering. Measurements reveal the presence of two diffusive modes: the slower mode is due to the motion of large globular aggregates while the faster mode is related to the motion of the self-assembled d(pG) columnar stacks. The behavior of the fast DLS mode is explained by the coupled mode theory, which relates the polyion motion with the dynamics of other ion species in the solution. The addition of 0.5 M KCl strongly promotes the self-assembly process resulting in a shift of the phase diagram towards lower d(pG) concentrations, while the properties of the two diffusive modes remain practically the same.