Tobias Ambjörnsson
Universitetslektor
Extension of nanoconfined DNA: Quantitative comparison between experiment and theory
Författare
Summary, in English
The extension of DNA confined to nanochannels has been studied intensively and in detail. However, quantitative comparisons between experiments and model calculations are difficult because most theoretical predictions involve undetermined prefactors, and because the model parameters (contour length, Kuhn length, effective width) are difficult to compute reliably, leading to substantial uncertainties. Here we use a recent asymptotically exact theory for the DNA extension in the "extended de Gennes regime" that allows us to compare experimental results with theory. For this purpose, we performed experiments measuring the mean DNA extension and its standard deviation while varying the channel geometry, dye intercalation ratio, and ionic strength of the buffer. The experimental results agree very well with theory at high ionic strengths, indicating that the model parameters are reliable. At low ionic strengths, the agreement is less good. We discuss possible reasons. In principle, our approach allows us to measure the Kuhn length and the effective width of a single DNA molecule and more generally of semiflexible polymers in solution.
Avdelning/ar
- Beräkningsbiologi och biologisk fysik - Genomgår omorganisation
- Fasta tillståndets fysik
- NanoLund: Centre for Nanoscience
Publiceringsår
2015
Språk
Engelska
Publikation/Tidskrift/Serie
Physical Review E (Statistical, Nonlinear, and Soft Matter Physics)
Volym
92
Issue
6
Dokumenttyp
Artikel i tidskrift
Förlag
American Physical Society
Ämne
- Nano Technology
- Biophysics
- Other Physics Topics
Status
Published
ISBN/ISSN/Övrigt
- ISSN: 1539-3755