DOI: 10.1140/epje/i2002-10150-9
Transverse fluctuation analysis of single extended DNA molecules
Z. Gueroui, E. Freyssingeas, C. Place and B. BergeLaboratoire de Physique (UMR CNRS 5672), Ecole Normale Superieure de Lyon, 46 Allée d'Italie, 69007 Lyon, France zoherg@rockefeller.edu
(Received 11 November 2002 and Received in final form 5 March 2003 / Published online: 4 June 2003)
Abstract
We observed fluctuations of
elongated DNA molecules by fluorescence microscopy. The molecules are fixed at both ends and undulate. Mode analysis of the
thermally excited
undulations of the labeled DNA molecules gives access to the
spectral density of the amplitude fluctuations. From these
measurements we estimate the tension acting on the DNA molecules.
We found the forces to be within the entropic elasticity range of a
typical DNA molecule (measured on the single-molecule level).
82.35.Pq - Biopolymers, biopolymerization.
87.15.Ya - Biomolecules: Fluctuations.
82.37.Rs - Single molecule manipulation of proteins and other biological molecules.
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2003