Isothermal amplification and quantification of nucleic acids and its use in microsystems

Nucleic acid amplification technologies (NAATs) offer the most sensitive tests in the clinical laboratory. These techniques are used as a powerful tool for screening and diagnosis of infectious diseases. Isothermal methods, as an alternative to polymerase chain reaction (PCR), require no thermocycling machine and can mostly be performed with reduced time, high throughput, and accurate and reliable results. However, current molecular diagnostic approaches generally need manual analysis by qualified and experienced personal which is a highly complex, time-consuming and labor-intensive task. Thus, the demand for simpler, miniaturized systems and assays for pathogen detection is steadily increasing. Microfluidic platforms and lab-on-a-chip devices have many advantages such as small sample volume, portability and rapid detection time and enable point-of-care diagnosis. In this article, we review several isothermal amplification methods and their implementation in microsystems in relation to quantification of nucleic acids.