Purification of an Enterobacter aerogenes plasmid DNA using MnCl2 as compaction agent

Development of an efficient process for purification of DNA plasmids continues to be a technological chal-lenge [1-3]. While earlier applications of DNA plasmids were mostly in cloning, the last few years have seen its increasing applications in gene therapy [1] and prepa-ration of DNA vaccines [4]. A crucial step in the pro-duction process is the downstream processing stage which encompasses separation of plasmid DNA from cellular components of the host strain (including chro-mosomal DNA and its fragments). In the case where the intended applications are in therapeutics, it is also nec-essary to separate the plasmid from materials such as toxic solvents, mutagenic reagents, and animal-derived enzymes (e.g., bovine pancreatic RNase A, used for re-moval of abundant RNA present in cell lysate) whic