Identification of M. tuberculosis complex by a novel hybridization signal amplification method

The objective of this study was to determine the sensitivity and specificity of hybridization signal amplification method (HSAM) assay for Mycobacterium tuberculosis complex (MTBC). This system consists of magnetic bead-linked capture probes for target isolation, dextran-based nanoparticles for amplifying the reporter molecule (biotinylated-FITC), and detection probes (2B-DNA) for binding the nanoparticles. Both the capture and detection probes were specific to the IS6110 target sequence. Our results determined that as few as 10 copies of the IS6110 sequence or 10 M. tuberculosis bacteria could be detected, indicating that the HSAM assay is as sensitive as conventional PCR, and the assay was specific enough to distinguish MTBC from nontuberculosis mycobacteria (NTM). This technique is highly sensitive and specific, is easy to perform, and does not require any sophisticated detection equipment; thus, this approach has great potential in clinical TB detection and diagnostic applications.