NZYMaxiprep Endotoxin Free kit was designed for the rapid, medium-scale preparation of highly pure plasmid DNA (typically 500 µg) from recombinant Escherichia coli strains, virtually free of endotoxins (<0.1 EU/µg plasmid DNA). Plasmid DNA binds selectively to NZYMaxi columns-Endotoxin Free charged with a silica-based anion-exchange resin. Effective washes allow the complete removal of contaminants, such as proteins, RNA, salts, nucleotides, oligos and endotoxins. The purified nucleic acid products are suitable to use in transfection of very sensitive cells like primary or neuronal cells. Using NZYMaxiprep Endotoxin Free kit, in two efficient washing steps, the plasmid DNA is eluted completely endotoxin free.