Fig. 4

Two-dimensional histograms with non-circular two-dimensional dot distribution and density plots of cases with non-normal distribution. Two-dimensional histograms with non-circular distribution using a schematic representation (A-C), and that of actual cases using density plots D-F; Blue color represents the highest density of the events in the cell population, and the color changes in the order of orange, light blue, pink, and green as the density decreases. This indicates that the cell clusters identified using flow cytometry are not always round, because they do not always have a normal (Gaussian) distribution. A-C The semi-elliptical (A) and the elliptical distribution (B, C) are overlayed with the main, single circular histogram (white dotted circle). D The single highest density area (blue, corresponding to that around the vertex of the distribution) is almost cohesive; however the left and right base distributions of the whole cell population is considerably more uneven than that of A and are not normally distributed. E The center of the highest density area and the vertex of the distribution is not clear because the distribution of blue dots is disorganized and wide. F There are two high-density areas (larger and smaller), each of which appears to have an overlapping base, resulting in a wide distribution as a whole