Abstract
Using a combined setup of tethered particle motion (TPM) with gold nano-beads and total internal reflection (TIR) illumination, we measured the three dimensional end-to-end distribution of a DNA tethered to a wall. Although the lateral Gaussian distribution is well known and studied, the axial distribution was never measured before.The planar distribution (parallel to the wall) is found to be Gaussian, with good agreement to both the worm like chain (WLC) model and the commonly sued Gaussian random walk (GRW) model. The axial distribution (perpendicular to the surface) is found to be Rayleigh-like, in agreement with WLC simulations. The distribution that is found with these WLC simulations, however, deviates systematically from the GRW distributions for short DNA strands (less than 3 micrometer).The WLC simulations reveal that the presence of the wall increases the correlations between the orientations of neighboring segments with respect to free DNA. It can also be interpreted as an entropic repulsion due to rejection of polymer conformations from the wall. This repelling potential might play an important role in the DNA functioning when it is close to the nucleus membrane.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
