Effects of PEG-rHuMGDF and of SCF, IL-3, and IL-6 on MK ploidy. MK ploidy was measured by a double staining technique with an FITC–anti-CD41b MoAb and propidium iodide solution using flow cytometry. The mean ploidy was calculated. The results are the average of six experiments performed starting with blood CD34⁺cells. Asterisks denote a significative difference (P < .05) in comparison with culture with 1 ng/mL PEG-rHuMGDF alone. (▤), MGDF; (▨), IL3; (▧), MGDF + SCF; (□), MGDF + SCF + IL6; (▪), MGDF + IL3; (▩), IL3 + SCF; (⊟), IL3 + SCF + IL6.