title: GSM8838715: HepG2-NTCP cells, McccDNA transfected; Homo sapiens; MNase-Seq
library_construction_protocol: Cell  were digested with trypsin, washed twice with PBS. The cells were then resuspended in PBS at a concentration of 10E6 cells/mL, with a reaction volume of 200 μL per sample. MNase lysis buffer (20 mM Tris-HCl, pH 7.5, 0.1% Triton X-100, 10 mM NaCl, 2 mM CaCl2) was added, and the cells were lysed on ice for 10 minutes. MNase (NEB, M0247S) was diluted to the appropriate concentration with MNase storage buffer, and samples were incubated at 37°C for 20 minutes. The reaction was stopped by adding 6.25 μL of 0.5 M EGTA, followed by 43 μL of PBS containing 1 mM EGTA. The mixture was then treated with RNase, and the reaction was stopped by adding a buffer containing 0.15% SDS and 0.25 mg/mL proteinase K. Subsequently, the samples were extracted with saturated phenol/chloroform, and nucleic acids were precipitated with ethanol. The DNA pellet was dissolved in ddH2O. Nucleosomal DNA monomers were purified by gel extraction, dissolved in TE buffer. MNase-seq libraries ware prepared using TIANSeq DirectFast Library Kit（illumina）from TIANGEN following manufacture's protocols.
identifiers.namespace: GEO
identifiers.id: GSM8838715_r1