Exonuclease I is used to selectively digest excess single stranded DNA in a mixture also containing double-stranded DNA, such as removing unused primers after PCR.
3'→5' single-stranded exonuclease.
Monomeric 54.5 kDa bacterial exonuclease I recombinantly expressed in E. coli.
Inactivated by heating at 80°C for 15 minutes.
Active in PCR buffers.
Exonuclease I, used together with Alkaline Phosphatase for inactivation of dNTPs, provides effective cleanup of PCR reactions for subsequent use in DNA sequencing.
Digestion of single stranded DNA by Exonuclease I releases dNTPs leaving 5'-terminal dinucleotides intact. DNA strands with terminal 3'-OH groups blocked by phosphoryl or acetyl groups are not removed.