Extremely thermostable proofreading, recombinant DNA polymerase, suitable for applications requiring high temperature synthesis of DNA. Unmodified enzyme replicates DNA at 74°C and exhibits over 95% activity after 1-hour incubation at 95°C. The enzyme catalyzes the polymerization of nucleotides into duplex DNA in the 5’→3′ direction in the presence of magnesium ions. The enzyme exhibits the 3’→5′ proofreading activity, resulting in over 10-fold higher PCR fidelity than possible with Taq DNA Polymerases. Pfu DNA Polymerase is recommended for use in high-fidelity PCR, PCR of GC-rich sequences or problematic secondary structures and cloning of blunt-ended PCR products.