Conformation of circular DNA in two dimensions.
The conformation of circular DNA molecules of various lengths adsorbed in a 2D conformation on a mica surface is studied. The results confirm the conjecture that the critical exponent nu is topologically invariant and equal to the self-avoiding walk value (in the present case nu=3/4), and that the topology and dimensionality of the system strongly influence the crossover between the rigid regime and the self-avoiding regime at a scale L approximately 7l{p}. Additionally, the bond correlation function scales with the molecular length L as predicted. For molecular lengths L<or=5l{p}, circular DNA behaves like a stiff molecule with an approximately elliptic shape.
Laboratoire de Physique de la Matière Vivante, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
Guillaume
G
Witz
Kristian
K
Rechendorff
Jozef
J
Adamcik
Giovanni
G
Dietler
D000327:Adsorption; D000538:Aluminum Silicates / Q000737:chemistry; D004270:DNA, Circular / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D008956:Models, Chemical; D009690:Nucleic Acid Conformation; D010957:Plasmids / Q000737:chemistry
D000538:Aluminum Silicates; D004270:DNA, Circular; C011934:mica