title: mouse heart EdU,EXP149_Heart_EdU_13
design: Mice were injected intraperitoneally with 25 mg/kg of EdU (disolved in PBS containing 5% DMSO) for 5 days at 24-h intervals, and tissues were harvested 24 h after the final injection.  Dissected mouse tissue samples were snap-frozen in liquid nitrogen and stored at -80C. For nuclei extraction, frozen tissues were placed inside aluminum foil, and smashed into powders with a hammer on dry ice. Then, transfer the powdered tissue into 10-20 mL nuclei lysis buffer [10 mM Tris-HCl pH 7.5 (VWR, 97062-936), 10 mM NaCl (VWR, 97062-858), 3 mM MgCl2 (VWR, 97062-848), 0.025% IGEPAL CA-630 (VWR, IC0219859650), 0.1% Tween-20 (Sigma, P9416-100ML), 1x cOmplete, EDTA-free Protease Inhibitor Cocktail (Sigma, 11873580001)], briefly vortex, and incubate for 10-15 minutes at 4C on a rotator. Extracted nuclei were then filtered through 40 m cell strainers (VWR, 470236-276).  EdU staining was performed on thawed nuclei using Click-iT Plus EdU Alexa Fluor 488 Flow Cytometry assay Kit (Thermo Fisher Scientific, 10633), and sorted for EdU positive nuclei.  Sorted nuclei were subjected to EasySci-ATAC-seq protocol (PMID: 38036784) for single-cell chromatin accessibility profiling.