Figure 3

Mechanical and Physical effects of SC4 on reconstituted chromatin. (A) Schematic representation of the injection of nucleosome on the bundle of DNA trapped by SNT tips. (B) Optical microscopy images at high (images at the top) and low (images at the bottom) magnification of DNA trapped by SNT in the microfluidic device after injection (from left to right) of (100 µM) nucleosome, water and (1 mM) SC4. White scale bars represent 10 µm. (C) Real time monitoring of the stiffness and viscous losses of DNA as the graph at the top. At first nucleosome was injected (0–320 s), which was followed by the consecutive injections of water (320–640 s), and SC4 (640–960 s) with an incubation times of 5 minutes each. The graph at the bottom zooms in the nucleosome and water injection periods. In black is shown the stiffness response and in red the viscous losses responses. pH value of each sample is represented by the universal color code of pH paper and indicated in the inset (green for neutral pH, red for acidic pH). pH data from all samples are given in Table S1.