Dpn I digestion

Purpose

To digest (Adeno) methylated GATC sites. Useful for removing cell-derived plasmid template from PCR samples.

Use

1. Add 1µL of DpnI to finished 50µL PCR reactions (or .5µL to 25µL reactions). Pipet or invert to mix.
2. Incubate the mixture at 37°C for 1-2 hrs (depending on your paranoia or need to remove template DNA). Alternatively, the solution can be left overnight at room temperature. Periodic mixing may aid digestion (but is unnecessary).
3. PCR cleanup or gel-purify the reaction for downstream processes. It's that easy!

Other Notes

DpnI can (and should) be added directly to PCR sample.

Outside of PCR reactions, use DpnI with NEBuffer 4 or Custmart.

Heat inactivate by incubating at 80°C for 20 minutes.

Procurement

Can be ordered directly from NEB.
Typically stored at -20°C; can be found in the common enzyme freezer box.

NEB unit definition:

One unit is defined as the amount of enzyme required to digest 1 µg of pBR322 DNA (dam methylated) in 1 hour at 37°C in a total reaction volume of 50 µl.

NEB buffer composition:

1X NEBuffer 4:
20 mM Tris-acetate
50 mM potassium acetate
10 mM Magnesium Acetate
1 mM Dithiothreitol
pH 7.9 @ 25°C