Microfluidic polymerase chain reaction

Abstract

We implement microfluidic technology to miniaturize a thermal cycling system for amplifying DNA fragments. By using a microfluidic thermal heat exchanger to cool a Peltier junction, we have demonstrated rapid heating and cooling of small volumes of solution. We use a miniature K-type thermocouple to provide a means for in situ sensing of the temperature inside the microrefrigeration system. By combining the thermocouple, two power supplies controlled by a relay system, and computer automation, we reproduce the function of a commercial polymerase chain reaction thermal cycler and demonstrate amplification of a DNA sample of about 1000 base pairs.

A Review of Heating and Temperature Control in Microfluidic Systems: Techniques and Applications

“…Indeed, the regulation of temperature is a critical parameter in managing many physical, chemical and biological applications. Prominent examples of applications requiring tight temperature control are Polymerase Chain Reaction (PCR) [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 ], Temperature Gradient Focusing for Electrophoresis (TGF) [ 16 , 17 ], digital microfluidics [ 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 ], mixing [ 32 , 33 , 34 ], and protein crystallization [ 35 ]. The scope of this article is to provide a comprehensive applications-based overview of heating techniques reported in the literature during the last decade.…”

Exploring the limits of ultrafast polymerase chain reaction using liquid for thermal heat exchange: A proof of principle

“…More recent advances include techniques for precise, rapid thermal control of nanoliter and microliter analyte volumes. [9][10][11][12][13][14] Traditionally, however, diagnostic tests are performed only in large, expensive thermal cyclers with slow thermal ramp rates that take about 1 h to complete a PCR amplification. This paper presents a method for ultrafast realtime thermal cycling through liquid thermal transfer.…”

Integrated microfluidic platform for instantaneous flow and localized temperature control

“…Existing global temperature control methods either preheat the carrying fluid 47 inside the device, or use a printed wiring board (PWB) heating unit under the entire microfluidic device 48 . Furthermore, the global temperature control usually measures the temperature outside the microchannel by using a thermocouple and utilizes a Peltier element to manipulate the temperature stage, leading to inaccurate temperature measurement inside the microchannel and causing slow cooling and heating at a rate around 10 • C/min, with temperature stability in the range of 1 • C. 55 As thermo-responsive physical phenomenon have drawn much attention in applications such as the stimuli of thermoresponsive polymers, 56 biological membrane response to temperature, 57 polymerase chain reaction (PCR), 18,19 and chemical reactions occuring at micron scales 18,20,21 . While precise temperature control can be accomplished by using global temperature control for devices on the order of ∼ 10 mm, it is challenging to achieve precise localized temperature control in a small and confined area (∼ 10 µm 2 ).…”