We developed protocols for isobaric TMT labeling on digital microfluidics (DMF) devices enabling the quantitative proteome analysis of approximately 25 mammalian cells per channel by subsequent bottom-up proteome analysis by LC-MS. This comprised identification of a compatible detergent for digestion, on-chip labeling, and LC-MS. Application of the method in a TMT 6-plex sample analysis enabled the relative quantification 648 proteins (2 unique peptides for quantification) from a total of 125 cell equivalents.