DNA Polymerase I (E. coli) is active in NEBuffers 1.1, 2.1, 3.1 and Cutsmart, as well as NEBuffers 1-4, however, optimal activity is observed in NEBuffer 2. All NEBuffers must be supplemented with dNTPs. To see its % functional activity in Cutsmart, and that of other DNA modifying enzymes in the cloning workflow, refer to the Activity of DNA Modifying Enzymes in CutSmart® Buffer chart.