Bst II Pro DNA Polymerase Large Fragment is obtained from the large fragment of Bacillus stearothermophilus DNA Polymerase by directed genetic engineering. It contains the 5´→ 3´ polymerase activity and strong strand displacement activity, but lacks 5´→3´ exonu_x005fclease activity. It is applicable for isothermal amplifications such as LAMP (Loop-Mediated Isothermal Amplification), HDA (Helicase-Dependent Amplification) and RCA (Rolling Circle Amplification). Compared with Bst II DNA Polymerase Large Fragment (Vazyme #P702), Bst II Pro DNA Polymerase Large Fragment combines a new generation of hot start technology to inhibit polymerase activity at temperatures below 50℃ and release polymerase activity at temperatures above 50℃. It has superior amplification speed, specificity, salt tolerance and thermal stability. The reaction system can be prepared at room temperature.