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Phys. Rev. Lett. 89, 188103 (2002) [4 pages]

Trapping of DNA by Thermophoretic Depletion and Convection

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Dieter Braun* and Albert Libchaber
Center for Studies in Physics and Biology, Rockefeller University, New York, New York 10021

Received 2 May 2002; published 14 October 2002

Thermophoresis depletes DNA from a heated spot. We quantify for the first time the thermal diffusion constant DT=0.4×10-8   cm2/s K for DNA, using fluorescent dyes and laser heating. For 5 kB DNA we extrapolate a 1000-fold depletion from a temperature difference of 50 K. Surprisingly, convection generated by the same heating can turn the depletion into trapping of DNA. Trapped DNA can form point geometries 20   μm in diameter with more than 1000-fold enhanced concentrations. The accumulation is driven only by temperature gradients and offers a new approach to biological microfluidics and replicating systems in prebiotic evolution.

© 2002 The American Physical Society

URL:
http://link.aps.org/doi/10.1103/PhysRevLett.89.188103
DOI:
10.1103/PhysRevLett.89.188103
PACS:
87.15.He, 82.70.Dd, 82.60.Lf

*Email address: mail@dieterb.de