32DA1 cells survive without IL-3. Control 32DV4 cells, as well as 32DA1.1, 32DA1.2, and 32DA1.3 cells were washed extensively in cytokine-free medium and plated in cytokine-free medium. The number of living cells in each culture was quantified daily by counting cells that were able to exclude Trypan blue (A). After 8 days in culture with (B) or without (C) IL-3, cytospin preparations were evaluated. Photomicrographs of the 32DA1.3 line are shown.