A short exposure of SKT6 cells to osmotic or heat shock induces erythroid differentiation rather than apoptotic cell death. (A) Left two panels: the hemoglobinized SKT6 cells stained with DAF after culture with or without Epo for 4.5 days. Right two panels: the hemoglobinized cells after treatment with 0.1 mol/L NaCl or 42°C for 1 hour, followed by incubation without Epo for 4.5 days. (B) The relative differentiation of SKT6 cells. Cells treated with 0.1 mol/L NaCl for 1 hour (lanes 3, 4), cells incubated at 42°C for 1 hour (lanes 5, 6), or untreated cells (lanes 1, 2) were cultured with (lanes 2, 4, 6) or without (lanes 1, 3, 5) Epo for 4.5 days and stained. The percentage of hemoglobinized cells in the presence of Epo is defined as 100%.