Divisional history of 1 single CD34⁺/CD38⁻ cell stained with PKH26, derived from an FLV sample. At 0 hour, a cell showing bright fluorescence is depicted. At 38 hours, the cell has divided, yielding 2 daughter cells with bright PHK26 fluorescence. At 98 hours, 1 cell has maintained bright fluorescence among 32 cells with dim fluorescence. On day 8 (at 194 hours), 1 cell with bright fluorescence has remained among several hundreds of other cells. The upper 4 pictures were taken with fluorescence microscopy. The bottom picture shows the same cell culture on day 8 in both phase contrast and fluorescence microscopy.