Add an equal volume of buffer-saturated phenol:chloroform (1:1) to the DNA solution.
Mix well. Most DNA solutions can be vortexed for 10 sec except for high molecular weight DNA which should be gently rocked. (If using Phase-Lock Gel, follow procedure )
Spin in a microfuge for 3 min.
Carefully remove the aqueous layer to a new tube, being careful to avoid the interface.
(Steps 1-4 can be repeated until an interface is no longer visible)
To remove traces of phenol, add an equal volume of chloroform to the aqueous layer.
phenol:chloroform (1:1)