Skewed Brownian Fluctuations in Single-Molecule Magnetic Tweezers
Measurements in magnetic tweezers rely upon precise determination of the position of a magnetic microsphere. Fluctuations in the position due to Brownian motion allows calculation of the applied force, enabling deduction of the force-extension response function for a single DNA molecule that is atta...
| Main Authors: | , , , |
|---|---|
| Format: | Online |
| Language: | English |
| Published: |
Public Library of Science
2014
|
| Online Access: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4180755/ |
| id |
pubmed-4180755 |
|---|---|
| recordtype |
oai_dc |
| spelling |
pubmed-41807552014-10-07 Skewed Brownian Fluctuations in Single-Molecule Magnetic Tweezers Burnham, Daniel R. De Vlaminck, Iwijn Henighan, Thomas Dekker, Cees Research Article Measurements in magnetic tweezers rely upon precise determination of the position of a magnetic microsphere. Fluctuations in the position due to Brownian motion allows calculation of the applied force, enabling deduction of the force-extension response function for a single DNA molecule that is attached to the microsphere. The standard approach relies upon using the mean of position fluctuations, which is valid when the microsphere axial position fluctuations obey a normal distribution. However, here we demonstrate that nearby surfaces and the non-linear elasticity of DNA can skew the distribution. Through experiment and simulations, we show that such a skewing leads to inaccurate position measurements which significantly affect the extracted DNA extension and mechanical properties, leading to up to two-fold errors in measured DNA persistence length. We develop a simple, robust and easily implemented method to correct for such mismeasurements. Public Library of Science 2014-09-29 /pmc/articles/PMC4180755/ /pubmed/25265383 http://dx.doi.org/10.1371/journal.pone.0108271 Text en © 2014 Burnham et al http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited. |
| repository_type |
Open Access Journal |
| institution_category |
Foreign Institution |
| institution |
US National Center for Biotechnology Information |
| building |
NCBI PubMed |
| collection |
Online Access |
| language |
English |
| format |
Online |
| author |
Burnham, Daniel R. De Vlaminck, Iwijn Henighan, Thomas Dekker, Cees |
| spellingShingle |
Burnham, Daniel R. De Vlaminck, Iwijn Henighan, Thomas Dekker, Cees Skewed Brownian Fluctuations in Single-Molecule Magnetic Tweezers |
| author_facet |
Burnham, Daniel R. De Vlaminck, Iwijn Henighan, Thomas Dekker, Cees |
| author_sort |
Burnham, Daniel R. |
| title |
Skewed Brownian Fluctuations in Single-Molecule Magnetic Tweezers |
| title_short |
Skewed Brownian Fluctuations in Single-Molecule Magnetic Tweezers |
| title_full |
Skewed Brownian Fluctuations in Single-Molecule Magnetic Tweezers |
| title_fullStr |
Skewed Brownian Fluctuations in Single-Molecule Magnetic Tweezers |
| title_full_unstemmed |
Skewed Brownian Fluctuations in Single-Molecule Magnetic Tweezers |
| title_sort |
skewed brownian fluctuations in single-molecule magnetic tweezers |
| description |
Measurements in magnetic tweezers rely upon precise determination of the position of a magnetic microsphere. Fluctuations in the position due to Brownian motion allows calculation of the applied force, enabling deduction of the force-extension response function for a single DNA molecule that is attached to the microsphere. The standard approach relies upon using the mean of position fluctuations, which is valid when the microsphere axial position fluctuations obey a normal distribution. However, here we demonstrate that nearby surfaces and the non-linear elasticity of DNA can skew the distribution. Through experiment and simulations, we show that such a skewing leads to inaccurate position measurements which significantly affect the extracted DNA extension and mechanical properties, leading to up to two-fold errors in measured DNA persistence length. We develop a simple, robust and easily implemented method to correct for such mismeasurements. |
| publisher |
Public Library of Science |
| publishDate |
2014 |
| url |
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4180755/ |
| _version_ |
1613139252622655488 |