Pfu

Pfu refers to both Pyrococcus furiosus, a hyperthermophilic archaeon, and the high-fidelity DNA polymerase derived from this organism. The term is commonly used in molecular biology to denote the Pfu DNA polymerase, an enzyme employed in polymerase chain reaction (PCR) that supports amplification with lower error rates than many standard enzymes.

Pyrococcus furiosus is a marine archaeon discovered in geothermally heated environments, such as hydrothermal vents. It grows optimally at around 100°C and is characterized as a strict anaerobe that metabolizes peptides and other carbon sources. The organism’s proteins, including its DNA polymerase, are highly thermostable, enabling their use in industrial and research applications that require enzymes to withstand high temperatures.

Pfu DNA polymerase is a thermostable enzyme that carries 3' to 5' exonuclease proofreading activity, contributing to its high fidelity during DNA synthesis. In PCR, Pfu polymerase produces fewer incorporation errors compared with non-proofreading enzymes such as Taq polymerase. Typical error rates for Pfu-based enzymes are on the order of 1 x 10^-6 to 3 x 10^-6 errors per base pair, significantly lower than those of many non-proofreading enzymes. While highly accurate, Pfu polymerase generally exhibits slower synthesis rates and may require longer extension times and optimized reaction buffers.

Applications of Pfu polymerase include routine cloning, high-fidelity DNA amplification for sequencing, site-directed mutagenesis, and other molecular biology techniques where precision is important. Several commercial variants and blends exist, some offering enhanced processivity or combined proofreading and strand-displacing capabilities. Pfu remains a standard choice when reducing amplification-induced errors is a priority in PCR-based workflows.