Figure 1

Data collected during CFSE-labeling experiments. Kernel density estimates of the log-transformed CFSE fluorescence intensity in live (Panel A) and in dead (Panel B) CD8+ T lymphocytes 64 hours after the start of the experiment. Each identifiable peak corresponds to one generation. The peaks are less distinguishable in dead cells than in live cells. Panel C shows a scatterplot of the log-transformed TOPRO-3 fluorescence intensity vs. the log-transformed CFSE fluorescence intensity in thousands of individual CD8+ T cells; the pool of cells expressing high TOPRO-3 are the dead ones, and the remaining cells are considered as alive. Panel D: scatterplots of side and forward scatters; examination of the plot enables to distinguish between cells, debris, and beads as shown.