DNA is wrapped around proteins called histones, which serve to package the DNA inside the cell nucleus. The basic unit of DNA packaging is the nucleosome, which is made up of eight histone proteins with DNA wrapped around them. The assembly of DNA and histone proteins is termed chromatin. Interactions of these molecules are essential for important processes like transcription, replication and DNA repair to take place. Understanding the location and nature of these interactions is therefore of significant interest for understanding the regulatory networks of these important cellular processes.