Rapid Detection of <i>Mycobacterium tuberculosis</i> Complex by Loop-Mediated Isothermal Amplification Combined with Chemosensor

Abstract

Loop-mediated isothermal amplification (LAMP) allowed rapid amplification of nucleic acids under isothermal conditions. It can be combined with a chemosensor for much more efficient, field-friendly detection of Mycobacterium tuberculosis complex. In this report, LAMP was performed at 65 °C for 10 min, followed by a rapid reaction of DNA amplification by-product, pyrophosphate ion, with chemosensor resulted in red disappearance. The detection limit of Mycobacterium tuberculosis complex by LAMP-Chemosensor was 3-5 copies, and the total assay time including 10 min for rapid DNA extraction was approximately 30 min. Data on naturally contaminated raw milk samples indicated that the LAMP method was highly specific and sensitive, giving 100% concordance with Real-time PCR. The results showed that the LAMP-Chemosensor method had the advantages of better sensitivity and speed and less dependence on equipment than the standard (PCR) for specifically detecting low levels of Mycobacterium tuberculosis complex DNA, and this can be useful in the field as a routine diagnostic tool.