FAQ: What is the difference between Exonuclease VII and Exonuclease I (NEB# M0293)?

Exonuclease VII can degrade ssDNA from both directions unlike Exonuclease I which works only from the 3' to 5' direction. Exonuclease VII can also degrade both 5' or 3' terminally phosphorothioated ssDNA-oligos. Exonuclease I is blocked by the presence of 3’ phosphorothioates.