Berlin 2018 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 9: Postersession I

BP 9.33: Poster

Montag, 12. März 2018, 17:30–19:30, Poster A

Investigating Compression of Single DNA Molecules in a Thermophoretic Trap — •Tobias Thalheim, Marco Braun, and Frank Cichos — Peter Debye Institute for Soft Matter Physics, Leipzig University, 04103 Leipzig, Germany

We report on the trapping of single DNA molecules in liquids with the help of a force-free trapping method utilizing feedback-driven dynamic temperature gradients. These temperature gradients, that are obtained by spatially and temporally vary the temperature at a circular plasmonic nano-structure, induce thermophoretic drift velocities which prevent the randomization of the positions and conformations of the DNA molecules due to Brownian motion. Because of the generated inhomogenous temperature profiles, drift velocities in the outer regions of the thermophoretic trap are larger than those in the center forcing the elongated DNA molecules into more compressed states of their conformation compared to freely diffusing molecules. A model-free statistical tool called principal-components analysis as introduced by Cohen and Moerner [1] is employed to assess these distortions of the DNA's conformation and conformation dynamics.

References

[1] A. E. Cohen, and W. E. Moerner, PNAS 104 (31),

12622-12627 (2007)