An integrated microfluidic system for identification of live mycobacterium tuberculosis by real-time polymerase chain reaction

Mycobacterium tuberculosis (TB) infection poses a huge challenge worldwide. It is challenging for rapid identification of TB due to its low growth rate, and therefore it could be widely spread. For this reason, a novel combination of propidium monoazide (PMA) and real-time polymerase chain reaction (RT-PCR) was reported in this work for fast detection of live TB. Experimental results showed that the PMA-RT-PCR protocol can detect live TB with a detection limit as low as 14 colony formation units (CFU)/reaction by measuring the threshold cycle number (Ct value) in a calibration curve. Furthermore, PMA could be used successfully to distinguish dead TB such that no PCR products could be generated. More importantly, all the procedure could be finished within 2 hours. This is the first time that an integrated microfluidic system was demonstrated to use molecular diagnostics for fast detection of TB and could be potentially used for prognosis monitoring of TB treatment.