excellent choice for cloning and other applications requiring high fidelity. Phusion DNA Polymerases offer robust performance with short protocol times, even in the presence of PCR inhibitors, and generate higher yields with lower enzyme amounts than other DNA polymerase.Phusion High-Fidelity PCR Master Mix is convenient 2X mix containing Phusion DNA Polymerase, nucleotides and optimized reaction buffer including MgCl2. Two master mix formulations are available - with HF Buffer (F-531S and F-531L) and with GC Buffer (F-532S and F-532L). The error rate of Phusion DNA Polymerase in HF Buffer (4.4 × 10-7) is lower than that in GC Buffer (9.5 × 10-7). Therefore, the master mix with HF Buffer should be used as the default master mix for high-fidelity amplification. However, GC Buffer can improve the performance of Phusion DNA Polymerase on some difficult or long templates, such as GC-rich templates or those with complex secondary structures.