Figure 2

Effect of verapamil on rhodamine exclusion by MDR-1-transduced cells. Rhodamine exclusion was performed in (a) the absence of verapamil and (b) the presence of 25 μM verapamil. Solid histograms indicate rhodamine fluorescence when no efflux time was allowed prior to FACS analysis. Open histograms indicate rhodamine fluorescence following efflux.