AS ONE PR Polymerase is a thermostable enzyme with PR ability, which can be used in primer extension reactions and other molecular biology applications. PR Polymerase exhibits both 5 prime to 3 prime DNA polymerase activity and 3 prime to 5 prime PR exonuclease activity. It is recommended for applications, which require extremely high fidelity or blunt ending. Optimal reaction conditions are achieved by using the 10x Ammonium buffer containing MgCl2 provided with the enzyme. 25 mM MgCl2 is also included separately, in case a higher MgCl2 concentration is required for a specific reaction.