Phase-Change Partitions for Thermal Automation of Multistep Reactions.

Medical diagnostics and basic research in low-resource settings require automated reactions to be controlled in a simple, portable manner. Here, we present a novel platform that enables simple automation of multistep reactions to facilitate robust, hands-free assay operation without complex microfluidics or paperfluidics. We separate reagent zones in a conventional PCR tube via solid layers of purified higher alkanes. Reagents can be mixed on demand by simply raising the temperature above the melting point of the alkane partition that separates the two zones. We partitioned various reagents to enable hands-free thermally automated isothermal nucleic acid amplification, heavy metal ion detection, and β-lactamase detection with tandem antibiotic specificity characterization. We anticipate that this phase-change partition platform will find broad application in clinical diagnostics at the point-of-care and in low-resource settings.