Isolation of Plasmid DNA

Abstract

There are many published protocols for isolation and purification of plasmid DNA. The theoretica basis for these procedures is described in Chapter 1. In most instances, plasmid DNA, isolated by these procedures, is of sufficient quality and quantity for cloning and PCR analysis. However, the plasmid DNA obtained by many of these methods is a poor template for double-stranded dideoxy DNA sequencing, largely due to inconsistency of template purity and yield. To obtain plasmid DNA of good quality for DNA sequencing, many sequencing protocols recommend the use of plasmid templates prepared by cesium chloride centrifugation or column chromatography. Although these methods give satisfactory results, they are time consuming, expensive and not suitable for preparation of templates from multiple samples.