An easy way to clean up DNA for sequencing is by PEG precipitation. Simply precipitate 4-8 µg plasmid DNA in a volume of 20 µl containing a final concentration of 0.4 M NaCl and 6.5% PEG for 15 minutes on ice. Pellet by centrifugation (15000 x g, 15 min, 4°C), wash the pellet with 70% ethanol, air dry and resuspend in 10 µl de-ionised water.

Hope this helps.

Thank you Dr.Christian Sepecht.