Average apparent stiffness of dead (dark gray) leukemic cells exposed to chemotherapy is significantly higher compared to untreated (light gray) cells (n > 15, p < 0.05 for all comparisons of dead/untreated populations). (A) Primary ALL cells and lymphoid leukemic cell lines exposed to 1 μM dexamethasone (B) Primary AML and myeloid leukemic cell lines exposed to 1μM daunorubicin. Error bars are standard error.