Parallel-processing continuous-flow device for optimization-free polymerase chain reaction

Construction of Very Low-Cost Loop Polymerase Chain Reaction System Based on Proportional-Integral-Derivative Temperature Control Optimization Algorithm and Its Application in Gene Detection

Real-time polymerase chain reaction (PCR) technology is essential in nucleic acid detection and point-of-care testing (POCT). However, nowadays, the classical qPCR instrument has the deficiency of its bulky volume, high cost, and inconvenience to use; hence, a low-cost and easy-to-use PCR equipment was thus developed consisting of a hardware subsystem as well as a software subsystem based on an improved proportional-integral-derivative (PID) system. The proposed system not only could hold self-setting reaction cycles of temperature rising and falling automatically but also the temperature during the constant temperature stage was regulated steady based on improved temperature control algorithm, which proved its great effect compared with the reaction temperature derived from an infrared thermal imaging camera. The experimental results in gene detection research also could indicate its applicability and stability of our developed PCR system by using the amplification curve analysis, the melting curve analysis, and agarose gel electrophoresis analysis compared with the commercial PCR instrument, which illustrates the great potential application value of the proposed PCR system.

Microchip for continuous DNA analysis based on gel electrophoresis coupled with co-injection of size markers and in-channel staining

A continuous-flow microchip enabling high-accuracy DNA analysis was developed. Serial consecutive analysis for multiple amplified DNA samples was demonstrated. The sample segments were continuously introduced to the microchip from the PCR device which was interfaced to the microchip through capillary tubing. Electrokinetic co-injection of the DNA samples with size marker enabled reproducible and reliable injection of the DNAs into the gel-filled separation channel providing accurate size determination of the DNA samples. Cross-contamination between serially introduced DNA samples was minimized by plugging a washing solution segment following the previous sample segment between two sample plugs. Using this microchip, continuous separation of multiple samples was performed without any inconvenient and labor-intensive sample preparation steps such as sample mixing, staining, and gel loading which are necessary for conventional gel electrophoresis. It has taken about 4 min to separate single DNA sample and taken 37 min for three serially injected samples which implies that this microchip can be a platform device for fast as well as highly accurate DNA analysis.