Figure 3.
Histogram matching: (a) Scatter plot tentry versus εmax/Δp for two K562 leukemia cell populations measured with wide (6 μm) and narrower (5.1 μm) constrictions. (Black lines) Fit of Eq. 1 to the data. (b) Strain histograms (left) and stress histograms (right) are shifted to higher values for cells in narrow constrictions (blue) compared to cells in wider constrictions (yellow). Areas where histograms overlap are marked (green). (c) Without histogram matching, cells measured in the narrower constrictions (blue) appear significantly (p < 0.05) stiffer (left) but have a similar fluidity (right) compared to cells measured in the wider constrictions (yellow). (d) Exemplary scatter plots and fit lines of the same measurements as (a) after Δp and εmax histogram matching. (e) Exemplary strain histograms (left) and pressure histograms (right) after histogram matching show perfect overlap for both cell populations. (f) After histogram matching, cells measured in the narrow (blue) and wider (yellow) constrictions both have similar elastic modulus (left) and fluidity (right) values. To see this figure in color, go online.