Fluorescence profiles of CFSE-labeled mouse lin⁻ BM cells.

Profiles shown are of cells before (left panel) and after (middle panel) FACS selection of the most brightly labeled subpopulation using a 30 channel-wide gate. The right panel shows the fluorescence profile of the cells recovered another 2 days later, after placing the selected CFSE⁺ cells (middle panel) into serum-free cultures containing FL, SF, and IL-11 either with (open peak) or without (solid peaks) colcemid. The distribution of cells according to the number of divisions they completed in the 2 days in culture after being labeled is shown by the different sized peaks corresponding to serial 2-fold decreases of fluorescence intensity. The fluorescence intensity of the cells incubated with colcemid confirms the position on a similar plot of the cells that had not divided.