Figure 2.

Recombinant anthrax lethal toxin decreases cellular invasion. (A) Representative micrographs of invaded cells on the bottom side of the collagen-coated membrane stained with cell stain according to assay instructions. SF268 treated with the toxin and control cells were allowed to invade towards 10% FBS for 24 h. Cells/ml (1×10⁶) were used in each assay. (B) Quantitation of (A) whereby the cell stain was solubilized using extraction buffer and absorption of cells suspensions were measured at 550 nm. Data are reported in arbitrary units and normalized to the control. Data are the mean ± SEM from three experiments.