The ITS graph provides a faithful representation of a chemical reaction, and thus in particular contains the necessary information to identify the reaction center. More precisely, the reaction center corresponds to a subgraph of the ITS containing at least all atoms incident to bonds that change during the transition from reactants to products. These subgraphs of the ITS are equivalent to the Double Pushout (DPO) graph rewriting rules used by the MØD package. Reaction centers embedded in ITS graphs, therefore, provide a source of reaction rules that can be used directly in large-scale computational applications.