Use of Atomic Force Microscopy to Characterize LPS Perturbations.

Lipopolysaccharide (LPS) on Gram-negative bacterial outer membranes is the first target for antimicrobial agents, due to their spatial proximity to outer environments of microorganisms. To understand the molecular nature and their interaction with antimicrobial agents, establishing a model LPS structure is of key importance. Here, we describe procedures for following LPS layer attachment to a solid surface and provide protocols for measuring bacterial membrane morphology after adding antibiotics. Using atomic force microscopy (AFM), we show methods to characterize the effects of antibiotic polymyxin B to the LPS layers at the nanoscale.