Single-cell mass cytometry sample preparation

Harvested cells were diluted to 10⁸ cells/1 mL PBS and centrifuged at 3200 × g for 10 min. The pelleted cells were re-suspended in cisPt solution (5 μM, 10 min, RT). Subsequently, the cisPt stained dead cells (cisPt+dead) were washed (3200 × g, 10 min) twice with 3 and 1 mL PBS, respectively, to remove unbound cisPt. Finally, cells were stained with RR (0.13 μM, 30 min, RT), washed twice (3200 × g, 10 min) with 1 mL water to remove salts and unbound RR. For mass cytometry measurement the cell concentration was adjusted to 5.0 × 10⁵ cells/mL in Milli-Q water. Four element calibration beads (Fluidigm, United States) were added 1:10 v/v before acquisition for later normalization (Finck et al., 2013 (link)).