Figure 5.

DNA promotes the liquid-liquid phase separation of MeCP2.

The synthesized DNA was labeled with DRAQ5. The in vitro phase separation assay at different conditions was done by incubation at room temperature for 45 min. Then, the mixtures were transferred to chambers made of double-sided tapes and sealed with coverslips. The fluorescent and DIC images were taken using the Nikon Eclipse TiE2 microscope. MeCP2: 3 µM, NaCl: 150 mM, no PEG.(A) Fluorescent images of MeCP2 droplets in the presence of DRAQ5 labeled DNA with different concentration and length. Scale bar = 10 µm.(B) Quantification of size, area and number of droplets from (A). The red channel was applied for droplet segmentation by bandpass filter and threshold based on the mean intensity in/out droplets. Droplets with size >0.1 µm2 were considered and droplet parameters were measured.≥3 images were taken for each condition. The droplets number and sum droplet area per image and mean droplet area were plotted with mean ± SD (standard deviation).