Figure 1. VMY induced cell death. The durability of effects of VMY on cell viability was determined via colony forming assays. D556 cells were treated with DMSO, PVB or VMY for 18 hrs. Fresh media was added and the cells cultured for an additional 3-5 days. (A) Cells stained with crystal violet. (B) Colonies as visualized by microscopy. (C) Quantification of colony number. (D) Quantification of cells per colony. The data are shown as average + standard deviation. PVB; purvalanol B, *; p<0.05.