Unlike the cleavage ends generated by most restriction enzymes, the ends generated by TelN Protelomerase are neither sticky nor blunt. The ends have hairpin structures with covalently closed ends that are resistant to digestion by exonucleases (e.g. Lambda Exonuclease, M0663 T5 Exonuclease, Exonuclease V, Exonuclease III, Exonuclease VIII (truncated) and T7 Exonuclease).