Fast Mutagenesis System. Primers anneal to the DNA template, mutant strands are synthesized with FastPfu DNA Polymerase. In vitro digestion of non-mutated parental plasmid (methylated plasmid) with DMT enzyme and in vivo degradation of non-mutated parental plasmid (methylated plasmid) with DMT Chemically Competent Cell, so as to efficiently select mutant clones. Mutation sites on both primers to improve the mutation efficiency. Partially overlapping primers for exponential DNA amplification. FastPfu DNA Polymerase has the extension rate of 4 kb/min. Double digestions (in vitro and in vivo) of parental plasmids to enhance mutation efficiency.