Purification of plasmid DNA using a multicompartment electrolyser separated by ultrafilter membranes

摘要

A simple, scalable method for purification of plasmid DNA is described. Plasmid DNA was released from Echerichia coli JM109 by lysis (1% SDS, 0.2 M NaOH). Then a neutralization solution (3 M sodijm acetate buffer, pH 4.8) was added to precipitate genomic DNA and protein. After the clarification of the lysate, the supernatant was placed in a multicompartment electrolyser separated by ultrafilter membranes to remove the remaining contamination (RNA, genomic DNA and protein). A recovery of 75% +- 2% of total plasmid DNA was obtained after 60 min electrophoresis with a field strength of 8 V cm~(-1) using cell at 30 g l~(-1) (quantified by dry cell weight). Genomic DNA, RND and protein were undetectable in the purified plasmid DNA solution.