Fig. 5. BC3 cells are killed by geldanamycin (GA). (A) Cytoplasmic extracts from BC3 cells treated with DMSO or GA were immunoprecipitated using the anti-vFLIP antibody and their GST-IB kinase activity measured. The viability of BC3 cells treated with increasing concentrations of GA or equivalent DMSO was evaluated by haemocytometer (B) and by propidium iodide (PI)/annexin V stain followed by FACScan analysis (C) at 48 hours. In each of the four graphs in C, the lower left quadrant represents live unstained cells, the lower right quadrant represents single stained early apoptotic cells, the upper right represents double stained, late apoptotic cells, and the upper left represents necrotic cells. (D) Graphical representation of the data in C.