Sat Apr 12 17:30:00 UTC 2025: ## Indian Scientists Develop Affordable, Rapid TB Diagnostic Test

**Thiruvananthapuram, India – April 13, 2025** – Researchers at the Sree Chitra Tirunal Institute for Medical Sciences and Technology (SCTIMST) have developed a new, cost-effective molecular test for the early diagnosis of tuberculosis (TB). The real-time loop-mediated isothermal amplification (rt-LAMP) assay boasts high sensitivity and specificity, rivaling existing methods like GeneXpert and Truenat, but at a significantly lower cost.

The rt-LAMP assay can detect TB DNA even at very low concentrations, delivering results within 10-20 minutes. Unlike traditional polymerase chain reaction (PCR) tests, it operates at a single temperature, simplifying the process and reducing the need for expensive equipment. The use of an inexpensive fluorescent dye further contributes to its affordability.

The test was evaluated against existing methods using 350 sputum samples, demonstrating slightly higher sensitivity and specificity than GeneXpert. It showed 89.36% sensitivity and 94.06% specificity compared to a microbiological reference standard.

The technology, developed as an open platform system, allows existing RT-PCR machines to be repurposed for TB diagnosis simply by adjusting the temperature setting. The assay facilitates high-throughput testing, capable of processing up to 384 samples simultaneously.

The rt-LAMP assay kit has received approval from the Central Drugs Standard Control Organisation (CDSCO) and is currently undergoing validation by the Indian Council of Medical Research (ICMR). The World Health Organization’s Health Technology Access Pool is also evaluating the technology.

This development is particularly significant for India, where a large percentage of presumptive TB cases (79%) are still diagnosed using less accurate sputum smear microscopy. While the number of molecular testing facilities has increased, it remains far from sufficient to meet national targets for reducing reliance on smear microscopy. The affordable and efficient rt-LAMP assay offers a promising solution to address this critical need.

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