GSM7518573: Input for Tbx3 ChIP-seq experiment; Mus musculus; ChIP-Seq
For intrahepatic delivery of the liver MPRA libraries, 8 to 10-week-old mice were secured and hydrodynamically injected with 20 µg of the libraries via the lateral tail vein. All libraries were diluted in sterile filtered 0.9% NaCl, and the total volume was adjusted to 10% (in mL) of the total body weight (in grams). 48 hours post-injection, mice were anesthetized by intraperitoneal injection of sodium pentobarbital (Nembutal, 50 mg/kg). Livers were perfused for 5 minutes with 40 mL of perfusion medium SC-1 (8 g/L Nacl, 400 mg/L KCl, 75.5 mg/L NaH2PO4, 120.5 mg/L Na2HPO4, 2,38 g/L HEPES, 350 mg/L NaHCO3, 190 mg/L EGTA, 900 mg/L D-(+)-Glucose, 1.2 mL Phenol Red solution) to remove the blood, followed by perfusion with 40 mL of SC-2 medium (8 g/L Nacl, 400 mg/L KCl, 75.5 mg/L NaH2PO4, 120.5 mg/L Na2HPO4, 2,38 g/L HEPES, 350 mg/L NaHCO3, 560 mg/L CaCl2.2H2O, 1.2 mL Phenol Red solution) containing 10 mg of collagenase P (Merck) for 5 minutes. Each lobe was dissected off and minced into small pieces in a beaker containing 39 mL SC-2 supplemented with 1 mL DNase I (Sigma-Aldrich) and 20 mg collagenase P, followed by rotating incubation for 15 min at 37°C. Hepatocytes were centrifuged for 2 min at 50 g, washed with PBS, centrifuged again for 2 min at 50 g, resuspended in 3 ml Hoechst buffer (DMEM + 10% FBS + 10 mM HEPES) and filtered through a 70 µm strainer. ChIP-seq was performed by following the Myers Lab ChIP-seq Protocol v011014 on 2x107 hepatocytes. Bethyl rabbit anti-TBX3 Ab (Sanbio A303-098A) was used for ChIP. 10 ng of immunoprecipitated DNA was used to perform library preparation according to the Illumina TruSeq DNA Sample preparation guide. Briefly, the immunoprecipitated DNA was end-repaired, A-tailed, and ligated to diluted sequencing adapters (1/100). After PCR amplification (18 cycles) and bead purification (Agencourt AmpureXP, Analis), the libraries with fragment size of 300-500 bp were sequenced using the NextSeq2000 (Illumina).