32D transfectants do not express globin. Cells were grown for 3 days in 10% WEHI conditioned media (as a source of IL-3) containing 0 (lane 1), 0.1 (lane 2), 0.5 (lane 3), 1 (lane 4), or 5 U/mL Epo (lane 5). The lysate from 1 × 10⁵ cells was electrophoresed in a 10% SDS gel and then immunoblotted with antimouse hemoglobin. Lane labeled “Ret” indicates mouse reticulocytes (1 × 10⁴ cells) as a positive control.