Figure 1.

(A) Demonstration of membrane resealing by flow cytometric analysis of propidium iodide influx into cells. THP cells were incubated with SLO at the given concentrations. Addition of propidium iodide after 10 min resulted in red fluorescence of permeabilized cells. After repair (t₁₂₀), the majority of cells treated with 20 ng/ml SLO became impermeable to the dye. (B) Proliferation assay. Flow cytometric analysis of 5-brom-2′-desoxyuridine incorporation performed after 2 h and 26 h following resealing revealed no difference to the controls. (C) Endocytosis assay. No alterations in endocytic uptake of FITC-dextran were observed by flow cytometry between toxin-treated and control cells.