High‐Throughput Dual Resonance and Non‐Resonance Mode Raman‐Activated Cell Sorting With Low‐Volume Harvesting

Abstract

ABSTRACT Raman‐activated cell sorting (RACS) platforms are limited by inflexibility in tackling different Raman signals and inability to export the sorted cells in a sufficiently low volume for downstream processing. Here, we present a generally applicable RACS platform that tackles these challenges. For adaptive dual‐mode operation that supports diverse spontaneous Raman signals, microfluidic optical tweezers are designed with switchable capture strategies, with a high‐throughput in‐stream mode (up to 834 events/min) for resonance Raman signals with short exposures (<0.1 s) for resonance‐Raman‐based screening, and a high‐precision out‐stream mode (up to 50 events/min) for non‐resonance Raman detection with extended exposures (>0.1 s). Moreover, to achieve low‐volume concentrated harvesting, an on‐chip storage and centralized harvesting mechanism delivers target cells in uniform 10 µL suspensions with >97% purity. Using the in‐stream mode for resonance Raman screening, we isolated a Yarrowia lipolytica mutant with 77% increased β‐carotene production in just one sorting round directly from a mutant library. Employing the out‐stream mode for non‐resonance Raman detection, we enriched phosphate‐solubilizing bacteria from wastewater with nearly 100% recovery in concentrated 10 µL volumes, enabling direct function‐targeted mini‐metagenomics. This high‐throughput dual‐mode RACS platform with low‐volume cell harvesting greatly expands the application of label‐free live‐cell sorting via metabolic phenome.