GSM8765279: CreP_3; Mus musculus; OTHER
control and tumor samples were roughly cut  with dissecting scissors  2 scalpels for approximately 10 min. Cell dissociation was performed by enzymatic digestion with 3mg/ml collagenase I (Roche, 11088793001) and 100U/ml hyaluronidase (Sigma-Aldrich, H3506) in complete media (HBSS (24020117), 5% SVF) during 1h30 under agitation at 170 rpm at 37°C. Thi step was followed by a second round dissociation under PBS 0,25% Trypsin-Versen (Thermo Fisher Scientific, 15040-033) prewarmed at 37°C for 1min30s with pipetting for 45s. The cell suspension was then treated with dispase 5 mg/ml (Sigma-Aldrich, D4693) and DNase 0,1 mg/ml (Roche, 11284932001) in complete media for 5 min at 37°C. A treatment with Red Blood cell lysis buffer (Thermo Fisher Scientific, 00-4333-57) was carried out then the suspension was filtered at 40µM before counting and FACS staining. Cell suspensions were stained 20 min in dark at 4°C with anti-CD45-APC 1:100 (BioLegend, 103112), anti-CD31-APC 1:100 (BioLegend, 102510), anti-CD24-BV421 1:50 (BioLegend, 101826), anti-CD49f-PE 1:50 (BioLegend, 313622). Cells were resuspended in cytometry media (PBS, BSA, EDTA). For the mammary gland samples, we either recovered the total epithelium or the luminal and basal cells populations separately. If the sample did not show nuclei aggregates, nuclei were loaded on a 10x Chromium system using 10x Chromium Single Cell ATAC–Seq kit v2 (10X Genomics) as described16. Final library amplification with 15 PCR cycles was performed according to the Chromium Single Cell ATAC Library kit manual. snCUT&Tag libraries were sequenced on a NovaSeq 6000 (Illumina) in PE50 mode.