Mass Activated Droplet Sorting (MADS) Enables High-Throughput Screening of Enzymatic Reactions at Nanoliter Scale.
Daniel A Holland-MoritzMichael K WismerBenjamin F MannIman FarasatPaul DevineErik D GuetschowIan MangionChristopher J WelchJeffrey C MooreShuwen SunRobert T KennedyPublished in: Angewandte Chemie (International ed. in English) (2020)
Microfluidic droplet sorting enables the high-throughput screening and selection of water-in-oil microreactors at speeds and volumes unparalleled by traditional well-plate approaches. Most such systems sort using fluorescent reporters on modified substrates or reactions that are rarely industrially relevant. We describe a microfluidic system for high-throughput sorting of nanoliter droplets based on direct detection using electrospray ionization mass spectrometry (ESI-MS). Droplets are split, one portion is analyzed by ESI-MS, and the second portion is sorted based on the MS result. Throughput of 0.7 samples s-1 is achieved with 98 % accuracy using a self-correcting and adaptive sorting algorithm. We use the system to screen ≈15 000 samples in 6 h and demonstrate its utility by sorting 25 nL droplets containing transaminase expressed in vitro. Label-free ESI-MS droplet screening expands the toolbox for droplet detection and recovery, improving the applicability of droplet sorting to protein engineering, drug discovery, and diagnostic workflows.
Keyphrases
- high throughput
- ms ms
- label free
- mass spectrometry
- single cell
- multiple sclerosis
- drug discovery
- liquid chromatography
- capillary electrophoresis
- gas chromatography
- machine learning
- high performance liquid chromatography
- high resolution
- hydrogen peroxide
- small molecule
- nitric oxide
- loop mediated isothermal amplification
- amino acid
- circulating tumor cells
- protein protein
- genome wide identification