Detecting Pathogen-Associated RNA via Piecewise Isothermal Testing achieving Sample-to-Result Integration

Banerjee, S.; Biswas, S. K.; Kedia, N.; Sarkar, R.; De, A.; Mitra, S.; Roy, S.; Bandopadhyay, A.; Banerjee, I.; Goswami, R.; Dutta, S.; Chawla-Sarkar, M.; Chakraborty, S.; Mondal, A.

We report a novel piece-wise isothermal nucleic acid test (PINAT) for diagnosing pathogen-associated RNA that embeds an exclusive DNA-mediated specific probing reaction with the backbone of an isothermal reverse-transcription cum amplification protocol as a unified single-step procedure. This single step sample-to-result test method has been seamlessly integrated in an inexpensive, scalable, pre-programmable and portable instrument, resulting in a generic platform technology for detecting nucleic acid from a wide variety of pathogens. The test exhibited high sensitivity and specificity of detection of SARS-CoV-2 infection when assessed using 200 double-blind patient samples, conducted by the Indian Council of Medical Research (ICMR), reporting a positive and negative percent agreement of 94.6% and 98% respectively. We also established its efficacy in detecting Influenza-A virus infection, performing the diagnosis at the point of collection with uncompromised detection rigor. The envisaged trade-off between advanced laboratory-based procedures with the elegance of common rapid tests renders the innovation to be ideal for deployment in resource-limited settings towards catering the needs of the underserved.