Portable Heating System Based on a Liquid Metal Bath for Rapid PCR

Area of Science:

• Biotechnology
• Molecular Biology
• Materials Science

Background:

• Accurate and rapid detection of novel coronaviruses is crucial for disease control, with polymerase chain reaction (PCR) being the standard nucleic acid detection method.
• The efficiency of PCR amplification is directly influenced by the temperature control precision and rate of temperature change in the thermal cycling device.

Purpose of the Study:

• To develop and optimize a new PCR method utilizing a liquid metal bath for precise and rapid temperature cycling.
• To evaluate the performance of a bismuth-based liquid metal bath compared to traditional silicone oil baths for PCR applications.

Main Methods:

• A novel PCR chip was designed and optimized using a liquid metal bath as the heat conduction medium, specifically a 47 °C bismuth-based liquid metal.
• Systematic exploration of liquid metals with varying melting points was conducted.
• Comparative analysis of thermal conductivity between the liquid metal bath and a thermally conductive silicone oil bath.

Main Results:

• The liquid metal bath system demonstrated a nearly threefold improvement in thermal cycle efficiency compared to the silicone oil bath.
• The liquid metal bath exhibited a fast average heating rate, excellent temperature control stability, reduced hysteresis, and a gentler temperature change curve, enhancing PCR amplification efficiency.
• Successful gene amplification was achieved using rat DNA and SEC61A as targets, demonstrating the system's applicability in PCR devices with various container types.

Conclusions:

• The liquid metal bath-optimized rapid PCR chip significantly improves temperature response speed, offering accurate data and reducing overall PCR time.
• This innovative method presents advantages of low cost, safety, environmental friendliness, and enhanced application efficiency.
• This study represents the first reported use of a liquid metal bath for rapid-cooling PCR.