Pfu DNA polymerase

Pfu DNA polymerase is a thermostable enzyme derived from Pyrococcus furiosus, used in PCR to amplify DNA with high fidelity. Unlike Taq polymerase, Pfu possesses 3' to 5' exonuclease proofreading activity, which reduces errors during DNA synthesis by removing incorrectly incorporated nucleotides. This results in an error rate of 1 in 1.3 million base pairs for Pfu-generated PCR products, compared to higher rates for Taq.

Pfu is slower than Taq, requiring approximately 1–2 minutes per cycle to amplify 1 kb at 72°C. It produces blunt-ended PCR fragments and is particularly suited for applications requiring high accuracy. Despite its lower speed, Pfu can be used alongside Taq to combine the fidelity of Pfu with the efficiency of Taq.

Discovered by Eric Mathur in 1991, Pfu was patented by Stratagene in 1996. Other Pyrococcus-derived polymerases, such as Deep Vent and Pwo, are also utilized in molecular biology applications.