Leukocyte classification method
Phase maps of labeled leukocytes of four different types from multiple donors were measured to construct the main dataset, including 857 monocytes, 738 granulocytes, 700 B lymphocytes, 821 T lymphocytes, 211 CD4 cells, and 220 CD8 cells. Representative phase maps for each leukocyte subtype are shown in Figure 2a. Based on these phase maps, area and dry mass distributions were generated for all the leukocyte types (Figure 2b, c). Note that cell dry mass quantifying the total protein content in a cell can be precisely determined from the phase map, and it has been well explored for cell phenotyping\cite{RN15,RN42}. As shown in Figure 2b, c, monocytes and granulocytes have similar areas but very different dry masses (p-value < 0.001), while they are well separated from all the other lymphocytes (B and T lymphocytes and CD4 and CD8 cells) through both area and dry mass distributions (p-value < 0.001). For the main subtypes of lymphocytes, i.e., B and T lymphocytes, they are different in both cell area and dry mass (p-value <0.001), but the differences are small. The subtypes of T lymphocytes, i.e., CD4 and CD8 cells, have similar cell dry mass and slightly different cell area distributions (p-value <0.001).