Diffusion of DNA in Nanoslits
| Autor: | Elizabeth A. Strychalski, Harold G. Craighead, S.L. Levy |
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| Rok vydání: | 2008 |
| Předmět: | |
| Zdroj: | Macromolecules. 41:7716-7721 |
| ISSN: | 1520-5835 0024-9297 |
| DOI: | 10.1021/ma801313w |
| Popis: | We observed the free diffusion of individual 10 kbp, (1/2)λ (24.2 kbp), and λ (48.5 kbp) double-stranded deoxyribonucleic acid (DNA) molecules in fused-silica nanoslits with depths from 541 to 24 nm using epifluorescence video microscopy. Diffusivity, D, scaled with nanoslit depth, h, according to D ∝ hα, where α was 0.47 ± 0.05, 0.51 ± 0.06, and 0.47 ± 0.05 for 10 kbp, (1/2)λ, and λ DNA, respectively, in disagreement with the value of two-thirds predicted by blob theory. We observed no change in scaling behavior for h less than the persistence length of DNA, as predicted by reflecting rod theory. The scaling of D with DNA length, N, followed D ∝ N−1, indicating hydrodynamic screening in accordance with Rouse dynamics. Our results establish these scaling exponents for smaller h and greater DNA confinement than previous studies. |
| Databáze: | OpenAIRE |
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