Figure 2

Accumulation of P-gp substrates in MCF7^WT cells and TS^WT. The accumulation of 5 μ M calcein-AM was determined in (A) monolayer cultures of MCF7^WT cells. The cellular levels of 2.5 μ M BODIPY-taxol were also measured in (B) monolayer or (C) TS systems. The fluorescent compounds were incubated with cells for 60 min at 37°C in a humidified atmosphere (5% CO₂). The images were obtained by confocal fluorescence microscopy and for TS they were taken from cells close to the tissue periphery.