DROP-LCMS for wastewater surveillance of viral disease

Wastewater surveillance programs enable large-scale analysis of viral pathogens, uncovering details such as mutation types and quantitative trends in infection prevalence. To enable sensitive and precise analysis of viral variants from wastewater in a streamlined and automated manner, we developed a multifunctional digital microfluidics-polymerase chain reaction-high performance liquid chromatography-mass spectrometry (DROP-LCMS) platform. This platform integrates a digital microfluidic system for droplet manipulation, automated pipetting, magnetic bead-based purification, and thermal control, with analysis by liquid chromatography-mass spectrometry. PCR and sample cleanup were effectively performed on the automated platform, and product droplets were directly sampled from the DMF device for LC-MS detection via a custom manifold. Using this system, we successfully detected the proportions of viral variants in wastewater, enabling effective tracking and monitoring of virus mutations and transmission, particularly during the early stages of the Omicron variant outbreak of SARS-CoV-2.