Figure 1

Phenotypic analysis of ex vivo Mk differentiation from CD34⁺ progenitor cells. Mobilized peripheral blood CD34⁺ cells were cultured in serum free media with an Mk-inducing cytokine cocktail of IL-3, Flt3-L and Tpo. (A) Percentages of viable cells expressing CD34 (squares) and CD41a (triangles) in Mk cultures, as assessed by flow cytometry (n = 3). The decline in Mk progenitor cell frequency, as measured by the CFU-Mk assay in a representative experiment (circles), slightly preceded loss of CD34 expression. (B) Wright-Giemsa stained cells from day 7 Mk culture displaying Mk cell morphological features. Image acquired with 63× objective shows representative field. Scale bar represents 20 μm. (C) The percentage of high ploidy (≥ 8N) among CD41a⁺ cells from one representative experiment (n = 3). Inset shows example DNA histogram and gating from day 12. (D) The percentage of apoptotic (Annexin V⁺/PI^-) cells among CD41a⁺ cells from one representative experiment (n = 3). Inset shows example scatter plot and gating from day 11.