Simultaneous removal of multiple DNA segments by polymerase chain reactions

Precise DNA manipulation is a key enabling technology for synthetic biology. Approaches based on restriction digestion are often limited by the presence of certain restriction enzyme recognition sites. Recent development of restriction-free cloning approaches has greatly enhanced the flexibility and speed of molecular cloning. Most restriction-free cloning methods focus on DNA assembly. Much less work has been dedicated towards DNA removal. Here we introduce a protocol that allows simultaneous removal of multiple DNA segments from a plasmid using polymerase chain reactions (PCR). Our approach will be beneficial to applications in multiple sites mutagenesis, DNA library construction, genetic and protein engineering, and synthetic biology.