Figure 8.

Flow cytometry PSC833 doses responses curves obtained by analyzing modal single cell fluorescence concentration (FL1-FC). Semilogarithmic doses responses curves showing the effect of increasing PSC833 concentrations on calcein accumulation in MCF-7/Doxo. Each point represents peak (modal) ± sem (10 independent experiments) of FL1-FC in MCF7/Doxo (a) or Hs578T/Doxo (b) expressed as the ratio of signal in the presence of PSC833 to signal in control conditions. Ligand binding sigmoidal doses responses curves were fitted to the data to obtain PSC833 potency (half-maximal effective concentration, EC₅₀) and efficacy (maximum response, E _max⁡).