Figure 3
From: Metabolic engineering of probiotic Escherichia coli for cytolytic therapy of tumors
In vitro toxicity of HlyE. (a) Examination of cell viability by trypan blue exclusion assay. After the treatment for 30 min, cell suspension was mixed with an equal amount of 0.4% trypan blue dye. The mixture was incubated 2 min at room temperature. 1, Mock; 2, LB medium; 3, extracellular HlyE from induced EcNe/HlyE; 4, intracellular HlyE from induced EcNe/HlyE. (b) Examination of cell viability by MTT assay. Tumor cells were treated with HlyE from induced EcNe/HlyE for 3 h. SW620 or HT29 cells were administrated with the various levels of HlyE as indicated. (c) Time-lapse images of cell morphology. Images of SW620 (upper) and HT29 cells (bottom) were taken over time as indicated on the left upon the HlyE treatment. The administration dose of HlyE was shown on the top of each panel. Arrows indicate internal rearrangement of organelles and loss of membrane integrity. Cell images were processed with GEN5 3.0 software (Biotek).
