DpnI Digest

DpnI is a restriction enzyme that cleaves methylated DNA. Treating PCR products with DpnI will therefore remove any template DNA derived from the bacteria. All the newly PCR-synthesised DNA will be unmethylated and thus unaffected.

1. Keeping the enzyme on ice, add 1 μl of DpnI to the PCR tube containing your sample. Gently invert a few times to mix contents.
   
   
2. Incubate at in a 37⁰c water bath for 60 mins.
   NOTE: The enzyme does not need to be removed, as in a conventional restriction enzyme digest, as it will be denatured by the SDS in the loading dye (if running on gel) or by the transformation conditions (if transforming straight into bacteria).