The following conditions can cause exonuclease activity to overwhelm the polymerase activity, causing recessed instead of blunt ends:
- Failure to add nucleotides, or the nucleotide concentration is too low
- Adding too much enzyme
- Incubating for too long
- Incubating at temperatures greater than the recommended temperature
- Heat inactivating without EDTA
Please see the recommended blunting protocol for
- DNA Polymerase I, Large (Klenow) Fragment by clicking here.
- T4 DNA Polymerase by clicking here.