Concentration-response curves are obtained by plotting <i>|Z|</i> at 2 MHz after exposing the cells to various concentrations of doxorubicin.

<p>The data was fitted to a sigmoid model. Based on the resulting fit, <i>IC₅₀</i> values were obtained as 0.4 µM and 70 µM for MCF-7 WT and MCF-7 DOX respectively. Data points (mean ± SEM, n = 5) were normalized to the magnitude value at t = 0 h.