phi29 DNA polymerase is a DNA polymerase cloned from Bacillus subtilis phage phi29 (Φ29) (1). On the one hand, the enzyme has excellent strand replacement and sustained synthesis capabilities, enabling the unstranding and replication of complex DNA structures and isothermal DNA polymerization reactions in vitro that do not depend on thermal cycling. On the other hand, the enzyme possesses 3′→5′ nucleic acid exonuclease proofreading activity.