Flow cytometric analysis and sorting windows of cells tracked with PKH26. (A) PKH26 fluorescence of freshly sorted Lin⁻Sca-1⁺c-kit⁺ cells stained with PKH26 on day 0. (B and C) PKH26 fluorescence of the cell populations after 7 days of suspension culture with TPO (B) or IL-6 and FL (C). Viable (PI-negative) cells were arbitarily divided into PKH26^low populations (I) and PKH26^highpopulations (II): BI, 89%; BII, 8%; CI, 94%; and CII, 2.7%.