Figure 3.

Time course of ciprofloxacin and minocycline accumulation by SCC-25 cells in the presence and absence of Na⁺. Confluent monolayer cell cultures were washed and overlaid with balanced salts solutions containing NaCl or choline chloride. Intracellular accumulation of ciprofloxacin or minocycline (30 μg/ml) was assayed at 37° C. Data are presented as the mean ± standard errors of three experiments.