Validation of the DSP protein profiling workflow. (A) ROI selection of FFPE HEK293 cell pellet slides. Circular ROIs of three different sizes (200 μm, 400 μm, or 600 μm in diameter) were selected on each slide, labeled as 001, 002, and 003, respectively. Cell nuclei were stained by STYO13 (blue) and cells were stained by fluorophore-labeled Pan-CK antibody (green). (B) Upper panel: Correlation of nCounter counts (y-axis) and ROI area (x-axis). Lower panel: nCounter counts of Ki-67 and Beta-2 microglobulin from three ROIs of different sizes normalized with housekeeping genes in duplicate slides (green and orange). (C) Volcano plot and box plots of individual proteins in HEK293 cells from duplicate slides. LogFC > 1 and p-value < 0.05 are denoted as significant. Data are FDR adjusted with blue and yellow representing individual slides.