Figure 7.

Intermethods comparison of PSC833 and verapamil doses responses curves expressed as mean fluorescence. Superimposed microplate reader and flow cytometry semilogarithmic doses responses curves showing the effect of increasing verapamil or PSC833 concentrations on calcein accumulation in MCF-7/Doxo (a) or Hs578T (b). Each point represents means ± sem (10 independent experiments) of cell-normalized well fluorescence (open circles) or flow cytometry mean FL1-FC (filled circles) expressed as the ratio of signals in the presence of blocker to signals in control conditions. Ligand binding sigmoidal doses responses curves were fitted to the data to obtain blockers potencies (half-maximal effective concentration, EC₅₀) and efficacies (maximum response, E _max⁡).