Figure 6.

Assessment of bacterial membrane integrity using flow cytometry. (a) Escherichia coli (KCTC 1682). (b) Staphylococcus aureus (KCTC 1621). Mid-logarithmic phase bacterial cultures were treated with 1× MIC of peptides, and cellular fluorescence was observed using a FACS scan flow cytometer. Membrane integrity damage was assessed by an increase in fluorescent intensity of propidium iodide (PI, 10 μg/mL) after incubation at 37 °C for 1 h. Control samples were processed without peptide treatment. This analysis provides quantitative data on the membrane-disrupting capabilities of the peptides against both Gram-negative and Gram-positive bacteria.