Apoptosis in Stat5a/b^{f/f; TC} and control adult splenic erythroid cells. (A) Freshly isolated splenic Ter119-positive cells were analyzed by FACS using an apoptosis detection kit and Ter119 staining. (B) After 24 hours in culture with Epo, cells were subjected to the same analysis. The left panels are from control mice; the right panels are from Stat5a/b^{f/f; TC} mice. Populations shown were gated as Ter119 positive and 7AAD negative. Representative profile from 1 of 3 individual experiments.