Plasmid DNA of high quality purified by activated charcoal

Abstract

Demand for plasmid DNA of high purity and safety has increased with rapid advances in gene therapy and DNA vaccines in addition to basic DNA study. Using activated charcoal (AC), we have developed protocols for pure plasmid DNA. Plasmid DNA extracted by the alkaline lysis method was inevitably contaminated with nucleotide fragments. Treatment with AC during purification instead of RNase completely removed nucleotide fragments in the final plasmid DNA and the removing capability of AC was dose dependent on AC quantity. Of note is that nucleotide fragments less than 0.4 kbp were effectively removed by AC and purification up to 500 ml was easily achieved. Taken together, inexpensive AC effectively removed the troublesome nucleotide fragments and practically substituted for expensive RNase. The resultant plasmid DNA has enough quality needed for basic DNA study and application.