A protocol for DNA fragment extraction from polyacrylamide gels

A simple and efficient method of purifying linear plasmid DNA from contaminating DNA fragments is described. Both vector and insert containing plasmids may be used without extensive purification, in particular without cesium chloride centrifugation. Careful deproteinization with phenol-chloroform allows efficient restriction enzyme digestion. Fragment separation can be performed immediately after restriction endonuclease digestion in a single 6% polyacrylamide gel. Extraction of DNA fragments from the gel is easy and gives a good yield. The DNA may be used for ligation and transformation without further purification.