Relaxation dynamics of partially extended single DNA molecules

Dynamical properties of chain molecules under tension are investigated using a functional integral formalism. The relaxation times of partially extended chain molecules are investigated on the basis of a Langevin equation approach and for the first time compared with experimental data of partially extended single DNA molecules. The hydrodynamic interaction as well as the semiflexibility of the molecules are taken into account. The theoretical approach quantitatively reproduces the experimental data. Furthermore, it is found that the normal mode concept also holds in the case of partially extended macromolecules.