title: GSM7604307: Rice Input_rep1; Oryza sativa; OTHER
library_construction_protocol: collected and cut into small slices of 1–1.5 cm in size, followed by cross-linking with a 1% final concentration of formaldehyde for 10 min under vacuum. DNA immunoprecipitation with anti-BG4 antibody coupled with sequencing termed BG4-DNA-IP-seq. Briefly, 5 μg of fragmented genomic DNA was denatured and reassociated in the G4 stabilization buffer (40% PEG200, 10 mM Tris-HCl, pH 7.5, with 150 mM KCl or NaCl), which was then followed by incubation with anti-BG4-FLAG antibody in the IP incubation buffer (50 mM HEPES, 150 mM KCl, 1 mM MgCl2, 130 nM CaCl2, 1% BSA, 40% PEG200, Complete Mini, pH 7.5). After adding anti-FLAG antibody (D110005, BBI, Shanghai, China) and washed protein G Dynalbeads (10004D, Invitrogen, Carlsbad, CA, USA) for additional 4 h followed by washing two times, anti-BG4 recognized DNA-G4s was finally recovered for library preparation. IPed and input DNA was used for library preparation using the NEBNext®Ultra™ II DNA Library Prep Kit for Illumina (E7645S, NEB). All libraries were sequenced on the Illumina platform.