BioReady Pfu is a thermostable enzyme of approximately 92 KD isolated from pyrococcus furiosus. BioReady Pfu catalyzes the DNA-dependent polymerization of nucleotide into duplex DNA in the 5'-3' direction in the presence of magnesium ions. The enzyme also exhibits 3'-5' exonuclease (proofreading) activity. The base misinsertions that may occur infrequently during polymerization are rapidly emendated by the proofreading activity of the polymerase. In generally, BioReady Pfu is mainly used for polymerization reactions requiring high fidelity synthesis.