Radial compression elasticity of single DNA molecules studied by vibrating scanning polarization force microscopy

Abstract

The radial compression properties of single DNA molecules have been studied using vibrating scanning polarization force microscopy. By imaging DNA molecules at different vibration amplitude set-point values, we obtain the correlations between radially applied force and DNA compression, from which the radial compressive elasticity can be deduced. The estimated elastic modulus is ∼20–70 MPa under small external forces (<0.4 nN) and increases to ∼100–200 MPa for large loads.