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AKB: Biologische Physik

AKB 15: Biopolymers II

AKB 15.5: Vortrag

Dienstag, 28. März 2006, 17:30–17:45, ZEU 260

Diffusion and intramolecular dynamics of double-stranded DNA in solution — •Eugene P. Petrov¹, Thomas Ohrt¹, Roland G. Winkler², and Petra Schwille¹ — ¹Institute of Biophysics / BIOTEC, TU Dresden, Tatzberg 47-51, 01307 Dresden — ²IFF, Forschungszentrum Jülich, 52425 Jülich

We present results of an experimental investigation of diffusional motion and intramolecular dynamics of double-stranded DNA molecules in solution at the room temperature. Dynamics of single-end fluorescently labeled lambda-DNA fragments with lengths covering the range of 10² to 10⁴ base pairs were studied by means of fluorescence correlation spectroscopy (FCS). Mean-square displacement of the fluorescently labeled end obtained from FCS data scales at short times as t^2/3, thus indicating the Zimm-type dynamics of the DNA polymer in solution. The experimental data are in a good agreement with the predictions of the theory of semiflexible polymers [1], which allows to extract diffusion coefficients and intramolecular relaxation times of DNA in solution from FCS measurements.

[1] L. Harnau, R.G. Winkler, P. Reineker, J. Chem. Phys. 104, 6355 (1996).