Long distance multiple-site directed plasmid mutagenesis by one-step PCR using non-overlapped primers.

Site-directed mutagenesis is a very important technique in molecular biological researches. We have developed a new method for long distance multiple-site plasmid mutation by one-step PCR using non-overlap primers. These primers were carefully designed and contained desired mutations in the middle of the primers flanked with 18-25 bp of correct sequence. One pair of the primers was able to generate a short megaprimer. Decreases in the concentrations of these primers increased efficiency of the multiple-site plasmid mutation. All of the mutant PCRs were performed at a common annealing temperature at 55 °C. This method could be widely used in all multiple-site plasmid mutations.