Taq DNA polymerase is a thermostable DNA polymerase of the thermophilic bacteria Thermus aquaticus. The enzyme catalyzes the 5’ to 3’ synthesis of the DNA without any detectable 3’ to 5’ proofreading (exonuclease) activity. Additionally, it exhibits significant deoxynucleotidyl transferase activity that adds extra adenines at the 3’ end of the PCR products. It is ideal for amplicons of 2kb or shorter.
Pfu DNA polymerase is a highly thermostable DNA polymerase of the thermophilic bacteria Pyrococcusfuriosus. The enzyme catalyzes a template-dependent 5’ to 3’ DNA synthesis with 3’ to 5’ proofreading (exonuclease) activity. It exhibits no 5’ to 3’ proofreading or exonuclease activity.