Microfluidic isolation of nucleic acids.

The detection of nucleic acids (NAs) within micro total analysis systems (μTASs) for point-of-care use is a rapidly developing research area. The efficient isolation of NAs from a raw sample is crucial for these systems to be maximally effective. The use of microfluidics assists in reducing sample sizes and reagent consumption, increases speed, avoids contamination, and enables automation. Through miniaturization into microchips, new techniques have been realized that would be unfavorable and inconvenient to use on a macroscopic scale, but provide an excellent platform for the purification of NAs on a microscopic scale. This Review considers the complexities of NA isolation with miniaturized and microfluidic devices, as well as the considerations when choosing a technique for microfluidic NA isolation, along with their advantages, disadvantages, and potential applications. The techniques presented include using silica-based surfaces, functionalized paramagnetic beads, oligonucleotide-modified polymer surfaces, pH-dependent charged surfaces, Al2O3 membranes, and liquid-phase isolation. This Review provides a basis to develop the chemistry to improve NA isolation and move it toward achieving 100% efficiencies.