Abstract

Chemically Programmable Isothermal PCR Enables Rapid Nucleic Acid-based Bioanalysis at the Point of Need

Victor Ugaz, Professor & Holder of the Charles D. Holland ’53 Professorship, Artie McFerrin Department of Chemical Engineering, Texas A&M University

The polymerase chain reaction (PCR) and its variants are analytical gold standards for nucleic acid-based testing that play a critical role in diagnosing and monitoring infectious diseases. But robust portable PCR-based testing at the point of need (PON) remains elusive, especially in resource-limited settings, because the required thermocycling instrumentation is neither amenable to nor validated for operation in a portable format. This presentation describes a microfluidic platform that overcomes these barriers by exploiting the ability to perform isothermal PCR via natural convection. We apply “chemical programming” to manipulate the interplay between the PCR biochemistry and the microscale convective flow field, enabling 100% repeatability to be achieved in a format that can be easily and cost-effectively manufactured, dramatically increasing simplicity, portability, and affordability. We demonstrate rapid replication of targets associated with multiple pathogens, including SARS-CoV-2, attaining performance rivaling ultra-fast PCR instruments while using lower reagent concentrations than conventional protocols. This discovery paves the way for widespread adoption of PCR-based analysis at the PON, making it possible to bring lab-quality diagnostics to decentralized settings.