The Silicon Review ^Asia

Tuberculosis is still a concern in India. As per reports, every year, the disease kills around two million people across the world. The major problem lies in detecting the disease at an early stage, to tackle this, a team of scientists from AIIMS (All India Institute of Medical Sciences) and THSTI (Translational Health Science and Technology Institute) has created a new testing method for detecting the dangerous disease faster.

Currently, TB can be detected through two methods, i.e. culture tests and sputum microscopy. However, culture tests require upto eight weeks to confirm the results and sputum microscopy is less sensitive. While conducting the conventional sputum tests, antibodies are used to detect bacterial protein in the sputum. But, both the tests have certain limitations like limited shelf-life, batch-to-batch variability,and cost.

In order to solve the problems, two new DNA aptamer-based-tests have been created by the researchers. The aptamer-based tests are ECS (Electromechanical Sensor) and ALISA (Aptamer Linked Immobilized Sorbent Assay). The scientists used the tests for detecting bacterial protein in the sputum.

Coming to the research part, ALISA was used to detect the bacterial protein (Hspx). To complete the test it took around five hours due to sputum immobilization (a time-consuming process). So, the researchers made efforts to create a simple ECS test. During the ECS test, aptamer and electrode were immobilized together, after that; aptamer was bind to Hspx in the sputum sample. After the process was completed, a drop in the electrical signal was recorded.

The results showed that ALISA responded well with 92 percent sensitivity as compared to the antibody-based method with 68 percent sensitivity.  The results were later published in the journal ACS Infectious Diseases and in Analytical Biochemistry respectively.

The whole research was led by Dr Tarun Sharma of AIIMS and other two- Dr Sagarika Haldar and Dr Jaya Tyagi from THSTI along with other members from both the institutes.