Pfu DNA Polymerase is a high-fidelity, thermostable enzyme of approximately 90kDa isolated from Pyrococcus furiosus. The enzyme replicates DNA at 75°C, catalyzing the polymerization of nucleotides in the 5´→3´ direction in the presence of magnesium. Pfu DNA Polymerase also possesses 3´→5´ exonuclease (proofreading) activity. Base misincorporations that may occur during polymerization are rapidly excised by this proofreading activity. Consequently, Pfu DNA Polymerase is recommended for use in PCR and primer extension reactions that require high-fidelity synthesis. Pfu DNA Polymerase-generated PCR fragments are blunt-ended. Pfu DNA Polymerase 10X Reaction Buffer with MgSO4: 200mM Tris-HCl (pH 8.8 at 25 degrees C), 100mM KCl, 100mM (NH4)(2)SO4, 20mM MgSO4, 1.0% Triton X-100 and 1mg/ml nuclease-free BSA.