Bst DNA polymerase is isolated from Bacillus stearothermophilus and is used for isothermal amplification. It is a thermostable DNA polymerase with strand-displacement properties and 5’-3’ polymerase activity, but lacks any 3’-5’ exonuclease activity (exonuclease minus).
Isothermal amplification such as loop mediated isothermal amplification (LAMP) is a DNA amplification technique that can be performed at a single temperature. LAMP is currently considered one of the most powerful isothermal amplification techniques, relying on a strand-displacement polymerase combined with four to six primers. These primers recognize several specific regions in the target DNA and two of the primers form loop structures to facilitate subsequent rounds of amplification producing high levels of DNA. Since the LAMP reaction is so robust, an extremely large amount of DNA is generated, specifically 1 to 10 copies of DNA can be amplified to 109 to 1010 copies often within 30 minutes, producing assays with excellent sensitivity and specificity.