Supplementary MaterialsS1: Supplementary Experimental Section and Supplementary Results (PDF) NIHMS1051229-supplement-S1
Supplementary MaterialsS1: Supplementary Experimental Section and Supplementary Results (PDF) NIHMS1051229-supplement-S1. the platform was applied to measure protein expression in 72 single cells from three murine cell populations (epithelial, immune, and endothelial cells) in 2 days instrument time with over 2,300 proteins identified. Principal component analysis grouped the single cells into three distinct populations based on protein expression with each population characterized by well-known cell-type specific markers. Our platform enables high throughput and unbiased characterization of single cell heterogeneity at the proteome level. embryos, where three blastomeres were quantified in single LY317615 (Enzastaurin) MS run.28 Recently, several TMT-based approaches have been developed that facilitate quantification of low abundance proteins. Russell et al. developed the TMTcalibrator? approach labeling diseased tissue in parallel with protein from body fluids.29C31 The high-level proteins in tissues facilitated the triggering of MS/MS fragmentation to enable quantifying of low-level proteins in body fluids. Budnik em et al /em .32 developed a single cell analysis method (SCoPE-MS) by implementing isobaric labeling of single cells in concert with 200 cells as carrier. Tian em et al /em .33 developed a deep proteomic analysis approach to discover single amino acid variants in a small numbers of cancer cells. Focusing on post-translational modification analysis, Yi em et al /em .34 developed a boosting to amplify signal with isobaric labeling (BASIL) strategy and applied it to study phosphoproteomic dynamics in mass-limited clinical specimens. Common to all these studies, a boosting sample containing much larger amount (30C500 fold) of peptide mass was labeled with one LY317615 (Enzastaurin) TMT channel and the mass-limited study samples had been labeled with the rest of the TMT channels from the multiplex arranged. The greater abundant increasing peptides provided wealthy fragment info for peptide recognition, while reporter ions offered quantification info for research examples. While these TMT-based increasing methods set up the feasibility of TMT labeling for proteomics analyses of Rabbit Polyclonal to MAPK1/3 mass-limited examples down to solitary cells, they have problems with the disadvantages of minute samples being processed conventionally uniformly. Particularly, the attendant test loses because of nonspecific adsorption/adhesion on areas. To handle this problem, we mixed the nanoPOTS strategy with TMT isobaric labeling technique, which was found in SCoPE-MS workflow previously, 32 to boost both proteomic test control evaluation and effectiveness throughput for solitary cells. Single cells had been isolated by movement cytometry, prepared in nanowells, tagged with TMT 10-plex, and mixed for LC/MS analysis finally. We systematically looked into the labeling reproducibility and the result of increasing ratios on solitary cell quantification. The optimized program was put on measure proteins manifestation in 72 solitary cells from three cultured murine cell populations (epithelial, immune system, and endothelial cells). We proven our solitary cell proteomics strategy provides deep proteome insurance coverage for solitary cell evaluation, can discriminate mammalian cell types and determine cell-specific proteins markers. Experimental Section Solitary cell isolation We used the BD Influx II cell sorter (BD Biosciences, San Jose, CA) to straight isolate solitary cells into nanowells.23 A customized matrix was produced in the cell sorter control software program to complement the nanowell array design. Fluorescent beads had been utilized to optimize sorting guidelines and to confirm successful deposition in each well. To select only viable cells, murine cells were labeled with a membrane-permeable live-cell labeling dye (100 LY317615 (Enzastaurin) nM, Calcein AM, eBioscience, Thermo Fisher) for 30 min in the dark. After cell collection, the nanowell chips were LY317615 (Enzastaurin) stored at ?80C or directly submitted for proteomic sample preparation. Proteomic sample preparation in nanodroplets The nanoPOTS-based proteomic sample preparation procedures were described previously.22 A home-built robotic liquid handling system was employed to dispense nanoliter reagents into nanowells for LY317615 (Enzastaurin) proteomic processing. The nanowell chip was placed in a closed chamber that was maintained at 95% relative humidity during dispensing procedures to minimize liquid evaporation in nanowells. The nanoPOTS-based sample preparation was carried out as the following steps. (1) Cell lysis, protein extraction, and disulfide reduction: 100 nL solution containing 0.2% DDM and 5 mM TCEP in 100 mM TEAB was added into each of the nanowells and the nanowell chip was incubated at 70 C for 30 min. (2) Alkylation of sulfhydryl groups: 50 nL 30 mM IAA in 100 mM TEAB was dispensed into each nanowell and the.