chromatin immunoprecipitation An immunoprecipitation in which chromatin (i.e. packaged DNA which can include protein and RNA complexes) is cut into short regions, reversibly cross linked, and antibodies or tags are used to select for pieces of chromatin with desired characteristics. Bjoern Peters, Randi Vita, James A. Overton ChIP OBI Yang et al, Int J Clin Exp Pathol. 2015; 8(3): 2746–275 PMID:26045780. Cells were lysed and sonicated to shear DNA to lengths between 200-1000 bp. The sample was then incubated with antibodies against Acety-H3 to immunoprecipitate protein-DNA complexes using protein A agarose beads. The isolated protein-DNA complexes were treated with proteinase K digestion to remove histones. QPCR was then performed using primers specific for TGF-β1, MMP-9 and PI3K promoters at 95°C for 5 min, followed by 40 cycles at 95 °C for 20 s, 58°C for 20 s, and 72°C for 20 s. Each QPCR reaction was repeated in triplicate. QPCR was followed by a melt curve analysis to determine the reaction specificity. The relative gene expression was calculated using 2-ΔΔCt method. chromatin immunoprecipitation immunoprecipitation metadata complete