  We study the rheology of semi-dilute solutions of the sodium salt of
calf-thymus DNA in the linear and nonlinear regimes. The frequency response
data can be fitted very well to the hybrid model with two dominant relaxation
times $\tau_{\circ}$ and $\tau_{1}$. The ratio $\frac{\tau_{\circ}}{\tau_{1}}
\sim$ 5 is seen to be fairly constant on changing the temperature from
20$^{\circ}$C to 30$^{\circ}$C. The shear rate dependence of viscosity can be
fitted to the Carreau model.
