Stretching tethered DNA chains in shear flow

• Published in: Europhysics letters Vol. 52; no. 5; pp. 511 - 517
• Main Authors: Ladoux, B, Doyle, P. S
• Format: Journal Article
• Language: English
• Published: Les Ulis IOP Publishing 01.12.2000; EDP Sciences; EDP sciences
• Subjects: 36.20.-r; 47.50.+d; 87.15.-v; Atomic and molecular physics; Biological and medical sciences; Biomolecules: structure and physical properties; Exact sciences and technology; Fluid dynamics; Fundamental and applied biological sciences. Psychology; Fundamental areas of phenomenology (including applications); General aspects; Macromolecules and polymer molecules; Molecular biophysics; Non-newtonian fluid flows; Physics; Studies of special atoms, molecules and their ions; clusters; Polymer solutions; Biological fluids; Molecular structure; DNA; Shear flow; Fluid flow; Non-Newtonian fluids; Experimental study; Stretching
• ISSN: 0295-5075; 1286-4854
• DOI: 10.1209/epl/i2000-00467-y

We discuss the stretching of tethered chains subject to a shear flow. Fluorescence microscopy measurements of the extension of sheared tethered DNA, “model polymers”, of various lengths are presented. The tethered chains approach full extension as the flow rate is increased, but very slowly. We show that a general theory to understand the large deformation of any sheared tethered chain must include both the correct nonlinear force-extension relation and chain fluctuations transverse to the flow direction, which themselves depend on the nonlinear elasticity of the chain. Direct comparison of derived scaling laws to simulations and experiments support our theory.