title: GSM1532318: WT-Zygote-rep2; Mus musculus; Bisulfite-Seq
library_construction_protocol: 5 µl of lysis buffer (20 mM Tris-EDTA [pH 8.0], 20 mM KCl, and 0.3% Triton X-100, 1 mg/ml QIAGEN Protease) was directly added to the frozen samples (in < 1µl PBS) followed by 3 hours of incubation at 50 ℃ and 30 minutes of inactivation at 75 ℃. Then to the same tube, 13 µl of MspI digestion master mix containing 10 units of MspI (Thermo Scientific) and 1.8 µl 10x Buffer Tango (Thermo Scientific) was added followed by 3 hours of incubation at 37 ℃ and 20 minutes of inactivation at 80 ℃. The digested DNA was then filled-in and tailed with an extra A to the 3’ end by adding 2 µl of end-preparation master mix containing 5 units of Klenow Fragment (exo-; Thermo Scientific), 1.8 µl of 10x Buffer Tango, 0.4 mM dATP, and 0.04 mM each of dGTP and dCTP (Thermo Scientific), followed by 40 minutes of incubation at 37 ℃ and 15 minutes of inactivation at 75 ℃. Adaptor ligation was then performed by adding 5 µl of ligation master mix, which contains 30 Weiss Units of T4 DNA Ligase (HC, Thermo Scientific), 0.5 µl of 10x Buffer Tango, 5mM ATP (Thermo Scientific), and 150 nM of methylated custom adaptor (Forward: 5’-ACACTCTTTCCCTACACGACGCTCTTCCGATC*T-3’, Reverse: 5’-/5Phos/GATCGGAAGAGCACACGTCTGAACTCCAGTC-3’, where * indicates phosphorothioate bond). After three incubation steps (16 ℃ for 30 min, 4 ℃ overnight, and 65 ℃ for 20 min), the reaction mix was subjected to EpiTect Fast Bisulfite Conversion Kit (QIAGEN) following manufacturer’s low-concentration protocol. The bisulfite converted DNA was immediately subjected to PCR amplification using KAPA HiFi HotStart Uracil+ ReadyMix (Kapa Biosystems) and NEBNext Primers for Illumina (New England Biolabs). After amplification, final libraries were obtained by size selection of 150-500 bp DNA fragments using SPRIselect beads (Beckman Coulter).
attributes.tag: GEO Accession
attributes.value: GSM1532318