Fig. 1

Main steps in the Hi-C protocol prior to sequencing. Chromatin is cross-linked and cleaved by a restriction enzyme. Interacting loci are held together in the same chromatin complex. Restriction fragment ends are filled in with biotin-labelled nucleotides and subjected to proximity ligation and shearing. Biotin-labelled ligation products are purified for paired-end sequencing. For simplicity, the steps after the restriction digest are only shown for one chromatin complex