The ChIP-exo Method: Identifying Protein-DNA Interactions with Near Base Pair Precision

J Vis Exp. 2016 Dec 23:(118):55016. doi: 10.3791/55016.

Abstract

Chromatin immunoprecipitation (ChIP) is an indispensable tool in the fields of epigenetics and gene regulation that isolates specific protein-DNA interactions. ChIP coupled to high throughput sequencing (ChIP-seq) is commonly used to determine the genomic location of proteins that interact with chromatin. However, ChIP-seq is hampered by relatively low mapping resolution of several hundred base pairs and high background signal. The ChIP-exo method is a refined version of ChIP-seq that substantially improves upon both resolution and noise. The key distinction of the ChIP-exo methodology is the incorporation of lambda exonuclease digestion in the library preparation workflow to effectively footprint the left and right 5' DNA borders of the protein-DNA crosslink site. The ChIP-exo libraries are then subjected to high throughput sequencing. The resulting data can be leveraged to provide unique and ultra-high resolution insights into the functional organization of the genome. Here, we describe the ChIP-exo method that we have optimized and streamlined for mammalian systems and next-generation sequencing-by-synthesis platform.

Publication types

  • Video-Audio Media

MeSH terms

  • Animals
  • Base Pairing*
  • Chromatin Immunoprecipitation / methods*
  • DNA / chemistry*
  • DNA-Binding Proteins / chemistry*
  • High-Throughput Nucleotide Sequencing

Substances

  • DNA-Binding Proteins
  • DNA