Isothermal Nucleic Acid Amplification System: An Update on Methods and Applications

Polymerase chain reaction is the most commonly used nucleic acid amplification for the diagnosis of several infectious and non-infectious diseases of animal and humans. But, it requires high expensive instrumentation for amplification and analysis. There are several isothermal amplification methods, such as Nucleic Acid Sequence Based Amplification (NASBA), Strand Displacement Amplification (SDA), Isothermal Multiple Displacement Amplification (IMDA), Rolling Circle Amplification (RCA), Helicase-Dependent Amplification (HDA), Single Primer Isothermal Amplification (SPIA), signal-mediated amplification of RNA technology, circular helicase dependent amplification, Recombinase Polymerase Amplification (RPA), Polymerase Spiral Reaction (PSR) and Loop-mediated Isothermal Amplification (LAMP). These methods can be amplified at a constant temperature by a simple water bath or heating block without use of high cost equipment’s like thermal cyclers and detection systems. The isothermal methods have been used for the detection of nucleic acids, proteins, enzymes and cancer cells. In this article, we reviewed the important isothermal amplification techniques and their applications in diagnosis and molecular biology.