An easy and very cheap way to clean PCR products before DNA sequencing
is to take 5 microliter of your PCR reaction and to add the following mix:
- 5 microliter water
- 1 microliter SAP (Shrimp alkaline phosphatase, 1 unit/microliter, to dephosphorylate the dNTPS)
- 0.1 microliter of ExoI (Exonuclease 1, 10 units/microliter, to digest remaining primers)
You can make a mastermix for the number of reactions you have to clean
and then add 6.1 microliter of the mix to each PCR reaction. Then
incubate for 30 minutes at 37°C for the reactions to occur and 20
minutes at 65°C to inactivate the enzymes (you can program your thermo
cycler for these two incubations).