Supplementary Figure 7: Mechanical phenotyping of cell types in whole blood.
From: Real-time deformability cytometry: on-the-fly cell mechanical phenotyping
In whole blood, in addition to white blood cells, also platelets and erythrocytes (red blood cells, RBC) can be found, with the latter being the largest fraction by far (RBC/other blood cells ~ 170:1). This poses the challenge whether any of the other cell types can be seen against the very large background of RBCs. To identify the remaining cells better, we reduced the number of RBCs by sedimentation in a dextran solution (see Online Methods for details) and measured the remaining sample. All samples shown in this figure were measured at a flow rate of 0.04 µl/s in a 20 μm × 20 μm channel. (a) RT-DC scatter plot of whole blood with most of the RBCs sedimented out. Here, the three remaining peaks are much more prominent (cf. Fig. 3d and Supplementary Fig. 6f,g). One of the remaining peaks can clearly be identified as platelets, based on their known very small size and separate RT-DC analysis (data not shown). Separation of (b) RBCs, (c) peripheral blood mono-nucleated cells (PBMCs; containing monocytes, lymphocytes, immature leukocytes) and (d) granulocytes (gran) by gradient density centrifugation, and subsequent RT-DC analysis clearly identified the remaining peaks. The correct relative numbers of these cells were confirmed with FACS analysis (see Supplementary Fig. 5b). (e) Isolated granulocytes were stimulated with phorbol-12-myristate-13-acetate (PMA), which resulted in a clear shift in their mechanical fingerprint. (f,g) RT-DC scatter plots of whole blood (diluted 1:50 in PBS – containing 0.5 % methylcellulose) from two different donors (in addition to the one in Fig. 3d) showing very little inter-donor variability of the relative positions of the four peaks.
