PURIFICATION OF SUPERCOILED PLASMID DNA

摘要

This invention comprises a process of purifying supercoiled plasmid DNA of purity and characteristics required for use in a DNA vaccine or in Gene Therapy or in uses where high purity supercoiled plasmid DNA is required, from a genetically transformed bacterium over-expressing the said supercoiled plasmid and the supercoiled plasmid DNA prepared by a process of this invention and products containing supercoiled DNA made by a process of this invention. The process of this invention comprises selective precipitation from a cell lyste of all DNA and endotoxin except supercoiled DNA by free metal ions. The said impurity comprising plasmid isoforms (linear, relaxed), genomic DNA, RNA, and an endotoxin from a host cell. The method is illustrated by using Cu2+ metal ions. The said Cu2+ metal ions were added as CuSO4 to reach to a final concentration of at least 0.5 M. The removal of metal ions is achieved by dialysis.