A paper-based device for tuberculosis diagnosis

Tuberculosis (TB) is the deadliest infectious disease today and India has the largest number of TB-related deaths among all countries in the world. The current state-of-the-art technology for rapid detection of TB is using ‘molecular diagnostics’, i.e. probing for the DNA of Mycobacterium tuberculosis (MTB), the TB-causing bacteria. Unfortunately, the World Health Organization-endorsed DNA-based TB test (GeneXpert) currently costs Rs. 1800 per test and is unaffordable to a majority of India’s population. Further, the GeneXpert instrument costs around Rs. 18 lakh and only an estimated 500 GeneXpert machines exist across India, too few to cater to the large Indian population. To overcome these limitations, we have invented a low-cost paper-and-plastic device that can detect the presence of TB DNA in liquid samples. An untrained user can perform a TB test by simply adding liquid samples to the paper reaction zones and placing the device in an incubator for 60-80 minutes. The results of the test are read using a cell phone camera installed within a small plastic box. The material cost of fabricating the device is only Rs. 61 and the cost of reagents per reaction zone is Rs. 41. The device eliminates all expensive instruments traditionally required for DNA-based amplification. A pilot clinical trial done in collaboration with CMC Vellore achieved 100% sensitivity for the detection of tuberculosis. The research work conducted by PhD student Navjot Kaur in the lab of Assistant Prof. Bhushan Toley in the Chemical Engineering Department was published in Scientific Reports on 25^th October.

Our paper can be accessed at : https://www.nature.com/articles/s41598-019-51873-8.

website URL : https://toleylab.weebly.com/