Detection of Mycobacterium tuberculosis by using loop-mediated isothermal amplification combined with a lateral flow dipstick biosensor

Tuberculosis is a persistent problem in the developing world and the biggest cause of mortality. Loop-mediated isothermal amplification (LAMP) allows DNA to be amplified rapidly at a constant temperature. Here a LAMP method was combined with a chromatographic lateral-flow dipstick (LFD) to detect IS6110 gene of M. tuberculosis rapidly and specifically. The reaction was optimized at 65 °C for 90 min and amplified DNA hybridized to an FITC-labeled oligonucleotide probe for 5 min was detected at LFD test line 5 min after application. Excluding for the step of DNA extraction, test results could be generated within 1 h 40 min. In addition to advantages of short assay time, confirmation of amplicon identity by hybridization and elimination of electrophoresis with carcinogenic ethidium bromide, the LAMP-LFD was more sensitive than an existing PCR assay for detection of M. tuberculosis.