Rapid and sensitive detection of the IS6110 gene sequences of Mycobacterium tuberculosis based on hybridization chain reaction and reusable magnetic particles

Mycobacterium tuberculosis (MTB) is the infectious pathogenic bacterium of tuberculosis, which is one of the major public health problems in the world. Until now, there remains a great challenge in the rapid, cost-saving and sensitive detection of MTB due to the strong infectivity and slow proliferation of MTB. In this manuscript, a cost-saving, enzyme-free and sensitive detection platform for the MTB IS6110 gene sequences (MTB DNA) was demonstrated by combining the superior separation ability of magnetic beads with the excellent signal amplification of hybridization chain reaction (HCR). The hairpin structure of H1 is destroyed by the hybridization of MTB DNA and H1 coupled with magnetic beads (MBs-H1) in present of MTB DNA, and HCR reaction is trigged. During this process, numerous TAMRA molecules are attached on the formed double-helix structure, and the fluorescence of the solution decreased after magnetic separation. Under the optimal conditions, the new method shows good fluorescence responses to MTB DNA with a lowest detectable concentration down to 10 pM. Importantly, the methodology can be further applied on the discrimination of DNA with single base-pair mismatches, which has great potential in single nucleotide polymorphism (SNP) analysis.