Miniaturized sample preparation on a digital microfluidics device for sensitive bottom-up microproteomics of mammalian cells using magnetic beads and mass spectrometry-compatible surfactants

We used digital microfluidics (DMF) for the sample preparation of approximately 100 mammalian cells, and subsequent bottom-up proteome analysis by LC-MS. This comprised optimization of cell lysis conditions for DMF, the development of detergent-buffer systems, and adaptation of the single-pot, solid-phase-enhanced sample preparation (SP3) approach on-chip. Application of the methodology to the proteome analysis of Jurkat T cells led to the identification of up to 2,500 proteins from approximately 500 cells, and up to 1,200 proteins from approximately 100 cells.