title: GSM7225386: OE-H3p3-noSort, rep3; Mus musculus; ATAC-seq
library_construction_protocol: For B cell isolation, splenic B cells were purified by the negative selection of CD43+ cells with anti-CD43 magnetic beads (Militenyi Biotec). The purified B cell population was>95% positive for CD19 staining. Cell sorting was performed on FACSMelody (BD Biosciences) to isolate the following populations: activated B cells (CD138lowB220hi) ; plasma cells (CD138hiB220low) and retrovirus-infected cells (GFP+) .For B cell stimulation assays, purified B cells were cultured in RPMI 1640 medium. For plasma cell differentiation, B cells were stimulated with 5 μg/ml of lipopolysaccharide (LPS). Assay for transposase-accessible chromatin sequencing (ATAC-seq):   ATAC-seq was performed following published protocol (Corces, M. et al., Nat Methods, 2017). 50,000 cells were used for each library. Chromatin integration labelling (ChIL):   ChIL-seq for B cells was performed described previously (https://doi.org/10.1038/protex.2018.122), except following. Cells were biotinylated for 30 min at 4°C with 1mg/ml sulfoNHS-SS-biotin in PBS and plated on streptavidin-treated 96-well plates (Thermo Fisher Scientific). After fixed with 1% paraformaldehyde (Electron Microscopy Sciences) in PBS for 5min at room temperature, fixation was stopped with 1 M Glycine/HCl.