Researchers in Taiwan have developed a simple, colour-based diagnostic approach with the potential to detect target DNA sequences found in tuberculosis-causing mycobacteria — in just a fraction of the time required for established diagnostic tests.

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More than a century after the identification of organisms that cause tuberculosis (TB), this disease remains a global public health challenge. According to World Health Organization estimates, there were 8.7 million new cases in 2011 and 1.4 million deaths. Most new cases occur in developing countries that lack the facilities and trained personnel required for early detection of TB.

In a study published in the journal Science and Technology of Advanced Materials (STAM), a team from four research organizations in Taiwan describe a simple, colour-based diagnostic approach with the potential to detect DNA sequences found in TB-causing mycobacteria — in just a fraction of the time required for established diagnostic tests.

The standard method for diagnosing TB involves culturing the Mycobacterium tuberculosis bacillus, which requires 3-6 weeks to grow on solid culture media or 9-16 days in rapid liquid culture media. A faster alternative is polymerase chain reaction (PCR) technology. However, this method is still too slow (turnaround time of 2-5 hours) and requires sophisticated infrastructure and trained personnel that might not be available in developing countries.

In their STAM paper, Tsung-Ting Tsai and colleagues employed gold nanoparticles and microfluidic paper-based analytical devices to achieve a rapid diagnosis without the need for complex and time-consuming laboratory processes. They easily detected target DNA sequences from TB mycobacteria, with a turnaround time of approximately one hour after the human DNA was extracted from patients.

Although the researchers are still optimising their technology, they believe that it will result in “affordable, sensitive, specific, user-friendly, rapid and robust, equipment-free, and highly end-user-deliverable diagnostic applications.”

 

 

For further information contact:

Mikiko Tanifuji
National Institute for Materials Science, Japan
Email: stam_office@nims.go.jp