Ordered Arrays of Native Chromatin Molecules for High-Resolution Imaging and Analysis

Aline Cerf, Harvey C. Tian, and Harold G. Craighead*

School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, United States

ACS Nano, Article ASAP

DOI: 10.1021/nn3023624

Publication Date (Web): July 21, 2012

Copyright © 2012 American Chemical Society

Individual chromatin molecules contain valuable genetic and epigenetic information. To date, there have not been reliable techniques available for the controlled stretching and manipulation of individual chromatin fragments for high-resolution imaging and analysis of these molecules. We report the controlled stretching of single chromatin fragments extracted from two different cancerous cell types (M091 and HeLa) characterized through fluorescence microscopy and atomic force microscopy (AFM). Our method combines soft lithography with molecular stretching to form ordered arrays of more than 250 000 individual chromatin fragments immobilized into a beads-on-a-string structure on a solid transparent support. Using fluorescence microscopy and AFM, we verified the presence of histone proteins after the stretching and transfer process.