Dynamics of Stretched Single DNA and Native Chromatin in Nanoslits

How external forces and confinements are coordinated is a fundamental question for biopolymer stretching in nanofluidics [1-2]. By applying micro-/nanofluidics, we study the dynamics of single DNA molecules and native chromatin fibers in nanofluidic channels. The DNA and chromatin fibers were stretched by attaching to microspheres held at the entrance of a nanoslit with external fields. The force-extension of DNA polymers in the nano-confinement slits was measured and described by using modified wormlike chain models. The DNA global persistence length increased as narrowing down the nanoslit height was provided, which verified the prediction of theories. [3] This device was used to electrophoretically stretch single native chromatin fibers extracted from human cancer cells by attaching the chromatin to microspheres held at the entrance of a nanoslit. To further demonstrate the potential for the device in epigenetics, the histone modification was optically detected. [4]
[1] J.W. Yeh, A. Taloni, Y.L. Chen, and C.F. Chou, Nano Lett. 12, 1597 (2012). (Nature 482, 442 (2012)) [2] A. Taloni, J.W. Yeh, and C.F. Chou, Macromolecules 46, 7989 (2013). [3] J.W. Yeh, K. Szeto, ACS Macro Letters 5, 1114 (2016). [4] J.W. Yeh, K. Szeto, Biomicrofluidics 11, 044107 (2017).