Droplet digital PCR applications in the tuberculosis world

Droplet digital polymerase chain reaction (ddPCR) is a third generation of polymerase chain reaction (PCR) that enables the exact quantification of nucleic acid targets within a sample. The capability of ddPCR to accurately detect and quantify low abundant targets has led to its fast-growing applications in detection of different pathogens. This review summarizes the ddPCR technology and its applications in tuberculosis diagnosis. From current studies including a total of 9 publications on the applications of ddPCR in tuberculosis research, it is clear that ddPCR technology offers enormous advantages, such as unparalleled sensitivity, high precision, and absolute quantification without a standard curve, over common molecular diagnostic platforms like the real-time quantification PCR. The latest study also showed that rapid drug susceptibility test of Mycobacterium tuberculosis in sputa could be achieved within 4 days. However, the high cost is the main limitation for its wide applications, especially in developing countries. As we near the vision 2030 goal for sustainable development and ending the tuberculosis epidemic by 2030, ddPCR techniques may help achieve this objective and many more discussed in the UNGA-HLM-TB.