Flt3-D835Y does not induce clonogenic growth of 32D cells in semisolid media. The 32Dcl3 cells stably expressing the indicated Flt3 constructs were plated in triplicate at a concentration of 1000 cells/dish. Colonies were analyzed on day 6. (A) Colony numbers. Each bar represents the mean ± SD of a representative triplicate experiment. (B) Low-power photograph of representative areas of the plates demonstrates the lack of colony growth in 32D/Flt3-D835Y in the absence of IL-3. Photographs of the colony assays were taken with an Olympus C5050 digital camera attached to an Olympus CKX1 inverted microscope equipped with an Olympus Plan 4 ×/0.1 objective lens (Olympus, Hamburg, Germany).