GSM9337265: ATAC - 8w-old cortex CxB rep3; Mus musculus; ATAC-seq
Dissected mouse cortices (two BxC and two CxB) were snap frozen in liquid nitrogen and stored at -80 °C. ATAC-seq library was prepared using the ActiveMotif ATAC-seq kit. Frozen mouse brains were minced with razor blade on ice and quickly transferred to conical tubes containing cold PBS. Tissue was centrifuged at 500 xg for 5 min at 4 C. PBS was discarded, and the pellet was resuspended in 1 mL ATAC lysis buffer. Lysis was assisted by dounce homogenizer with tight fitting pestle for 30 strokes. Samples were filtered through 40 μm strainer into a new conical tubes. Nuclei were counted using trypan blue, and 100,000 nuclei were transferred to a new tube. Nuclei were centrifuged at 500 xg for 5 min at 4 C, and supernatant was discarded. Nuclei pellets were subject to tagmentation at 37 C for 30 min with gentle shaking at 800 rpm. Immediately following the tagmentation reaction, total DNA was extracted using columns. Purified DNA was PCR amplified using proper index primers. Then, the PCR reaction was purified using SPRI beads. Samples were pooled equimolar. Sequencing was performed PE150.