DNA Elasticity Flaw

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JILA scientists have discovered a flaw in a common model for DNA elasticity.

This discovery may improve the accuracy of single-molecule research and pave a way for DNA to become an official standard for measuring picoscale forces.


JILA is a joint venture of the National Institute of Standards and Technology (NIST) and the University of Colorado at Boulder.


The JILA experiments, described in a new paper,* reveal that a classic model for measuring the elasticity of double-stranded DNA leads to errors when the molecules are short. For instance, measurements are off by up to 18 percent for molecules 632 nanometers long, and by 10 percent for molecules about twice that length. (By contrast, the DNA in a single human cell, if linked together and stretched out, would be about 2 meters long.)


The JILA group collaborated with theorists from the universities of Colorado and Pennsylvania. The work was supported by the Alfred P. Sloan Foundation, a Burroughs Wellcome Fund Career Award in the Biomedical Sciences, the Butcher Foundation, a W.M. Keck Grant in the RNA Sciences, NIST, and the National Science Foundation.


Read the Paper - Refence:

Elasticity of short DNA molecules: theory and experiment for contour lengths of 0.6--7 µm. Y. Seol, J. Li, P.C. Nelson, T.T. Perkins and M.D. Betterton. Biophysical Journal. Published on-line in BioFAST, Aug. 31, 2007.