A temperature control method for shortening thermal cycling time to achieve rapid polymerase chain reaction (PCR) in a disposable polymer microfluidic device

Abstract

We present a temperature control method capable of effectively shortening the thermal cycling time of polymerase chain reaction (PCR) in a disposable polymer microfluidic device with an external heater and a temperature sensor. The method employs optimized temperature overshooting and undershooting steps to achieve a rapid ramping between the temperature steps for DNA denaturation, annealing and extension. The temperature dynamics within the microfluidic PCR chamber was characterized and the overshooting and undershooting parameters were optimized using the temperature-dependent fluorescence signal from Rhodamine B. The method was validated with the PCR amplification of mecA gene (162 bp) from methicillin-resistant Staphylococcus aureus bacterium (MRSA), where the time for 30 cycles was reduced from 50 min (without over- and undershooting) to 20 min.

Comparison of Ultrasonic Welding and Thermal Bonding for the Integration of Thin Film Metal Electrodes in Injection Molded Polymeric Lab-on-Chip Systems for Electrochemistry

“…For these reasons, UW is compatible with the pre-loading of temperature-sensitive materials or even of biological material, such as DNA [15]. Recently, UW has been used (amongst other techniques) for the assembly of piezo micropumps [16], to perform polymerase chain reaction (PCR) [17], and in combination with TB [18,19,20]. …”

A rapid microfluidic platform with real-time fluorescence detection system for molecular diagnosis

“…The two curves followed the same pattern at the points of temperature variation, and there was no overshoot at any turning point. This will contribute to enhancing the amplification efficiency and shortening the reaction time [23]. Particularly, the cooling rate of this platform can reach 3.1 degrees per second, and the heating rate can even reach 5.3 degrees per second, which was superior in the performance compared to traditional tubular PCR devices [24].…”

Molding and bonding of thermoplastic microfluidic devices

“…Recently, this method has been introduced to weld microparts for microfluidic applications [159,[161][162][163][164][165]. These microparts were joined together by the molten micro energy directors, which could localize ultrasonic energy and weld the bonding surfaces.…”

“…In recent research [167][168][169][170], ultrasonic energy has been introduced in rapid bonding of flat thermoplastic microfluidic substrates at low temperature. In contrary to microwave bonding [242][243][244] and ultrasonic welding [159,161,165], there is no polymer melting involved in this promising bonding process [167]. It was reported that the proposed thermal assisted ultrasonic bonding can ultrasonically bond PMMA substrates at temperature 20−30 °C lower than its Tg in tens of seconds with good bond strength and minor microchannel deformation [170].…”

“…According to ASTM international standard designation E1640, the glass transition shall be taken as the extrapolated onset to the sigmoidal change in storage modulus observed in going from the rigid region to the rubbery region of the thermoplastic being tested by DMA. 165…”