Exploration of isothermal nucleic acid amplification techniques in the biomedical field

Nucleic acid amplification techniques (NATs) are frequently used in the molecular biology arena. Polymerase chain reaction (PCR) and its variants are one of the most popular NATs. The requirement of a sophisticated thermocycler and skilled technician for PCR limits its use in resource-limited laboratories and fields. Alternatively, the isothermal amplification technique can also deliver proficiency, simplicity, sensitivity, and fidelity without the need for the thermocycler. Several isothermal methods have been devised and newer concepts are also emerging. Some of them are loop-mediated isothermal amplification, whole genome amplification, rolling circle amplification, nucleic acid sequence-based amplification, and polymerase spiral reaction. These cost-effective, practicable, and easy-to-perform diagnostic assays are in current trends to identify pathogens, tumors, embryo sex, and genetically modified organisms. Isothermal amplification can also be used in microfluidic devices and point-of-need diagnostics. This review focuses on the development of common isothermal processes, their characteristics, and their acceptance over the PCR.