For blunting reactions requiring removal of overhangs: DNA Polymerase I, Large (Klenow) Fragment can be used in NEBuffers r2.1, r3.1, and rCutSmart Buffer as well as NEBuffers 2, 3, and 4 and T4 DNA Ligase Buffer. NEBuffers r1.1 and 1 are not recommended when overhang removal is required. Optimal activity is observed in NEBuffer 2. Supplementation of dNTPs is required for all blunting reactions.
It can also be used in rCutSmart Buffer. To see its % functional activity in rCutSmart, and that of other DNA modifying enzymes in the cloning workflow, refer to the Activity of DNA Modifying Enzymes in rCutSmart® Buffer chart.