Sample Pretreatment and Nucleic Acid-Based Detection for Fast Diagnosis Utilizing Microfluidic Systems

Abstract

Recently, micro-electro-mechanical-systems (MEMS) technology and micromachining techniques have enabled miniaturization of biomedical devices and systems. Not only do these techniques facilitate the development of miniaturized instrumentation for biomedical analysis, but they also open a new era for integration of microdevices for performing accurate and sensitive diagnostic assays. A so-called "micro-total-analysis-system", which integrates sample pretreatment, transport, reaction, and detection on a small chip in an automatic format, can be realized by combining functional microfluidic components manufactured by specific MEMS technologies. Among the promising applications using microfluidic technologies, nucleic acid-based detection has shown considerable potential recently. For instance, micro-polymerase chain reaction chips for rapid DNA amplification have attracted considerable interest. In addition, microfluidic devices for rapid sample pretreatment prior to nucleic acid-based detection have also achieved significant progress in the recent years. In this review paper, microfluidic systems for sample preparation, nucleic acid amplification and detection for fast diagnosis will be reviewed. These microfluidic devices and systems have several advantages over their large-scale counterparts, including lower sample/reagent consumption, lower power consumption, compact size, faster analysis, and lower per unit cost. The development of these microfluidic devices and systems may provide a revolutionary platform technology for fast sample pretreatment and accurate, sensitive diagnosis.

An integrated lateral flow assay for effective DNA amplification and detection at the point of care

“…Conventionally, nucleic acid amplification and detection (e.g., polymerase chain reaction (PCR) and electrophoresis) are separately performed, which are costly, labour-intensive, time-consuming and large equipment dependent, reducing their suitability for point-of-care (POC) applications. [4][5][6] Nowadays, there exist a number of nucleic acid-based diagnostic equipment available in the market with the ability to perform isothermal amplification (e.g., loop-mediated isothermal amplification (LAMP) and recombinase polymerase amplification (RPA)) 7,8 and/or amplicon detection. For instance, isothermal amplification with real time detection has been implemented in several systems such as the SAMBA system by Diagnostics for the Real World (UK), Loopamp real-time turbidimeter (LA-200) by Eiken (Japan), Twista portable real-time fluorometer by TwistDX (UK) and bioluminescence assays in a real-time (BART) instrument by Lumora (UK).…”

New frontiers in microfluidics devices for miRNA analysis

“…The ion depletion feature of the membrane, on the other hand, helped exclude all charged molecules at a precise location in the microfluidic channel, reducing diffusion time to the sensor and resulting in rapid target detection. These steps are much simpler and less expensive than the hydrodynamic, mechanical, acoustic, electric, magnetic bead, and ultrasonic approaches used in other similar LOCs [66,67]. Moreover, the absence of any electron transfer reaction on the membrane surface has turned such sensors into highly stable measurement tools.…”

Integrated, DC voltage-driven nucleic acid diagnostic platform for real sample analysis: Detection of oral cancer

“…Recently, several sample pretreatment lab-on-a-chip techniques have been developed to process real biological samples including hydrodynamic, mechanical, acoustic, electric, magnetic bead, and ultrasonic approaches [4,26,29,30]. Some of these lysing methods require complicated metal electrode fabrication, expensive instrumentation and multistep protocols [30].…”

“…Some of these lysing methods require complicated metal electrode fabrication, expensive instrumentation and multistep protocols [30]. Here, we demonstrate an easy-to-integrate, on-chip sample pretreatment process to extract nucleic acids from real samples by integrating gel electrophoresis into our microfluidic platform.…”