Loop-mediated isothermal amplification of DNA (LAMP): a new diagnostic tool lights the world of diagnosis of animal and human pathogens: a review

Abstract

Diagnosis is an important part in case of animal husbandry as treatment of a disease depends on it. Advancement in molecular biology has generated various sophisticated tools like Polymerase Chain Reaction (PCR), its versions along with pen-side diagnostic techniques. Every diagnostic test however has both advantages and disadvantages; PCR is not an exception to this statement. To ease the odds faced by PCR several non-PCR techniques which can amplify DNA at a constant temperature has become the need of hour, thus generating a variety of isothermal amplification techniques including Nucleic Acid Sequence-Based Amplification (NASBA) along with Self-Sustained Sequence Replication (3SR) and Strand Displacement Amplification (SDA) and Loop mediated isothermal amplification (LAMP) test. LAMP stands out to be a good and effective diagnostic test for empowering in developing countries as it does not require sophisticated equipments and skilled personnel and proves to be cost-effective. Performance of LAMP mainly relies on crafting of six primers (including 2 loop primers) ultimately accelerating the reaction. LAMP amplifies DNA in the process pyrophosphates are formed causing turbidity that facilitates visualisation in a more effective way than PCR. The Bst and Bsm polymerase are the required enzymes for LAMP that does not possess 5'-3' exonuclease activity. Results can be visualized by adding DNA binding dye, SYBR green. LAMP is more stable than PCR and real-time PCR. Non-involvement of template DNA preparation and ability to generate 10(9) copies of DNA are added benefits that make it more effective than NASBA or 3SR and SDA. Thus, it fetches researcher's interest in developing various versions of LAMP viz., its combination with lateral flow assay or micro LAMP and more recently lyophilized and electric (e) LAMP. Availability of ready to use LAMP kits has helped diagnosis of almost all pathogens. LAMP associated technologies however needs to be developed as a part of LAMP platform rather than developing them as separate entities. This review deals with all these salient features of this newly developed tool that has enlightened the world of diagnosis.