The morphology of circular DNA deposited from a solution on the mica surface is analyzed from the power spectrum density (PSD) of the atomic force microscopy (AFM) images. Sample morphology is modulated in a broad range of concentration C from isolated molecules to highly entangled networks. DNA exhibits a multiaffine behavior with two correlation length scales: the persistence length P which remains constant (?50 nm) within the C range and the intermolecular distance ? which exhibits a decay with increasing C. Applying a diffusion based model in which ? scales as ? ? D-0.25·C-0.5, we extracted the DNA diffusion coefficient D ? 2 × 10-7 cm2/s. This value is consistent with a high-molecular-weight plasmid DNA supercoiled in the solution.
Measurement of DNA Morphological Parameters at Highly Entangled Regime on Surfaces
Stoliar P;Bystrenova E;Valle F;Biscarini F
2009
Abstract
The morphology of circular DNA deposited from a solution on the mica surface is analyzed from the power spectrum density (PSD) of the atomic force microscopy (AFM) images. Sample morphology is modulated in a broad range of concentration C from isolated molecules to highly entangled networks. DNA exhibits a multiaffine behavior with two correlation length scales: the persistence length P which remains constant (?50 nm) within the C range and the intermolecular distance ? which exhibits a decay with increasing C. Applying a diffusion based model in which ? scales as ? ? D-0.25·C-0.5, we extracted the DNA diffusion coefficient D ? 2 × 10-7 cm2/s. This value is consistent with a high-molecular-weight plasmid DNA supercoiled in the solution.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
