UV–Vis Spectra-Activated Droplet Sorting for Label-Free Chemical Identification and Collection of Droplets

We introduce the UV–vis spectra-activated droplet sorter (UVADS) for high-throughput label-free chemical identification and enzyme screening. In contrast to previous absorbance-based sorters that relied on single-wavelength absorbance in visible range, our platform collects full spectra from 200 1050 nm at up 2100 per second. Our custom-built open-source software application, “SpectraSorter,” enables real-time data processing, analysis, visualization, selection of droplets sorting with any set spectral features. An optimized detection region extended path length allowed direct protein quantification down 10 μM bovine serum albumin 280 nm. can distinguish a variety different chemicals or spurious events (such as air bubbles) are inaccessible single wavelength. The is used measure ergothionase activity monoclonal microcolonies isolated droplets. manner, we directly ergothioneine substrate thiourocanic acid product conversion while tracking microcolony formation. UVADS represents an important new tool in-droplet analysis.