Immobilizing live bacteria for AFM imaging of cellular processes

Area of Science:

• Microbiology
• Biophysics
• Materials Science

Background:

• Studying bacterial cellular processes requires stable cell anchoring for high-resolution imaging.
• Traditional methods like porous membranes or soft gels can perturb cells or introduce confinement effects.
• Atomic force microscopy (AFM) offers high-resolution imaging but requires secure cell immobilization.

Purpose of the Study:

• To develop a non-perturbing method for anchoring bacterial cells for AFM imaging.
• To enable the observation of cellular processes, such as cell division, in immobilized Staphylococcus aureus.
• To minimize confinement effects often associated with bacterial cell trapping techniques.

Main Methods:

• Mechanical trapping of coccoid Staphylococcus aureus cells within lithographically patterned substrates.
• Imaging of trapped cells under growth media using atomic force microscopy (AFM).
• Utilizing non-chemical linkages to the substrate to avoid cell perturbation.

Main Results:

• Successful mechanical entrapment of Staphylococcus aureus cells in patterned substrates.
• AFM imaging of trapped cells revealed they could undergo cell division.
• The non-perturbing entrapment method allowed bacteria to continue normal cellular processes.

Conclusions:

• Lithographically patterned substrates offer a novel and effective method for anchoring bacterial cells for AFM studies.
• This technique minimizes cell perturbation and confinement effects, allowing for more natural observation of cellular processes like division.
• The developed method provides a stable platform for long-term AFM imaging of live bacteria.