Deep Vent DNA Polymerase was the second high-fidelity thermophilic DNA polymerase available from New England Biolabs. The fidelity of Deep Vent DNA Polymerase is derived in part from an integral 3´→ 5´ proofreading exonuclease activity. Deep Vent is even more stable than Vent at temperatures of 95 to 100°C.