Isothermal nucleic acid amplification techniques: A comprehensive overview on their principle & applications as alternative to PCR

Abstract

Isothermal nucleic acid amplification methods have gained prominence as a valuable innovation in molecular diagnostics. These methods function at a constant temperature without the requirement of thermal cycler apparatus, simplifying the amplification process and making them strong alternative to PCR, particularly in resource limited areas where quick, affordable, and straightforward nucleic acid amplification technique is needed. Over the past 20 years, various isothermal nucleic acid amplification techniques have been developed, among them loop-mediated isothermal amplification (LAMP), helicase-dependent isothermal DNA amplification (HDA), rolling circle amplification (RCA), strand displaced amplification (SDA), nucleic acid sequence-based amplification (NASBA) and recombinase polymerase amplification (RPA) are commonly used techniques to enable quick and easy detection of target nucleic acid. This approach simplifies molecular diagnostics, enabling broader access to genomic testing in various fields of research and clinical practice. Many researches and review articles have been published since isothermal amplification is developed. However, there is lack of comprehensive review to cover common isothermal amplification mechanisms, detection methods, and applications together. Therefore, this review provides a comprehensive overview on common isothermal amplification techniques as alternative to PCR by focusing on their advantages, reaction principles, product detection, applications in disease diagnosis, as well as IAM future perspective.