Broad-Temperature Polymerase in Nucleic Acid Amplification-Based Diagnostics: From Thermal Precision to Dynamic Conditions.

Polymerases play a fundamental role in nucleic acid amplification acting as the catalytic engine driving DNA synthesis. While polymerase chain reaction (PCR), the traditional nucleic acid amplification method, relies on thermostable polymerases and precise thermal cycling through three temperature phases, isothermal methods such as loop-mediated isothermal amplification (LAMP) employ polymerases with strand-displacement activity to operate at a constant temperature. In this study, we introduce a LAMP-based amplification method that enables nucleic acid amplification across a broad temperature spectrum, from 39 to 75 °C, using a Bst polymerase with robust strand displacement activity and broad thermostability. We demonstrate that amplification can be initiated at both high and low starting temperatures and maintained even under dynamic temperature profiles. This broad-temperature-range amplification system was successfully applied to the detection of SARS-CoV-2 and M. tuberculosis genomic DNA and offers a promising platform for point-of-care diagnostics and field applications where strict thermal control is not feasible.