High-Fidelity DNA Polymerases are important for applications in which the DNA sequence needs to be correct after amplification. Phusion High-Fidelity DNA Polymerase offers both high fidelity and robust performance, and thus can be used for all PCR applications. Its unique structure, a novel Pyrococcus-like enzyme fused with a processivity-enhancing domain, increases fidelity and speed. Phusion DNA Polymerase is an ideal choice for cloning and can be used for long or difficult amplicons. With an error rate >50-fold lower than that of Taq DNA Polymerase and 6-fold lower than that of Pyrococcus furiosus DNA Polymerase, Phusion is one of the most accurate thermostable polymerase available. It possesses 5' to 3' polymerase activity, 3' to 5' exonuclease activity and will generate blunt-ended products. Phusion High-Fidelity PCR Master Mix with GC Buffer is a 2X master mix consisting of Phusion DNA Polymerase, deoxynucleotides and reaction buffer that has been optimized and includes MgCl2.