Thermo Scientific Exonuclease I (ExoI) degrades single-stranded DNA in a 3'→5' direction. It releases deoxyribonucleoside 5'-monophosphates in a stepwise manner and leaves 5'-terminal dinucleotides intact.

It does not cleave DNA strands with terminal 3'-OH groups blocked by phosphoryl or acetyl groups.

Highlights

• Active in PCR buffers

Applications

• Primer removal from PCR mixtures:
• prior to PCR product sequencing
• for one-tube 'megaprimer' PCR mutagenesis

• Removal of single-stranded DNA containing a 3'-hydroxyl terminus from nucleic acid mixtures
• Assay for the presence of single-stranded DNA with a 3'-hydroxyl terminus

Note

The enzyme is not suitable for removing 3'-overhangs of dsDNA.