Fast and accurate method for quantitating E-coli host-cell DNA contamination in plasmid DNA preparations

Plasmid DNA is being used successfully as a gene delivery vector in a varie ty of clinical applications. Similar to other pharmaceutical products for c linical use, the plasmid vectors must meet rigorous purity standards. One i mportant contaminant is the DNA of the host cell used to produce the plasmi ds. We have developed a new method to accurately quantitate E. coli host-ce ll DNA in plasmid-preparations. This method is based on kinetic PCR using t he ABI PRISM(R) 7700 with 23S rDNA as a target. This precise assay is signi ficantly faster and has a lower limit of quantitation than the currently us ed Southern-based methods.