4.3. Cell Viability

Cell proliferation was conducted on suspension cells and was determined by the trypan blue dye exclusion test as described previously [21].

All of the cells (K562, TCCY-T315I, Ba/F3-T315I, Y253H, and E279K) that live on the signal induced by BCR–ABL overexpression were used in the research, while the un-transfected Ba/F3 cells were not used because their growth was dependent on the signal induced by IL3. The selectivity index (SI) was expressed as IC₅₀ value of Vero cell/IC₅₀ value of cancer cell line. The SI values indicate MeST selectively kill leukemia cells and not just non-selective cytotoxic extracts. Samples with an SI value >3 were considered highly selective for cancer cells [22].