Facile method to stain the bacterial cell surface for super-resolution fluorescence microscopy.

Area of Science:

• Microbiology
• Biophysics
• Nanotechnology

Background:

• Super-resolution microscopy requires precise cell surface labeling.
• Existing methods may not be universally applicable to both Gram-positive and Gram-negative bacteria.
• Visualizing nanomaterial interactions with bacterial surfaces at high resolution is challenging.

Purpose of the Study:

• To present a novel fluorescent staining method for bacterial cell surfaces.
• To demonstrate compatibility with super-resolution fluorescence microscopy techniques.
• To enable detailed visualization of bacterial cell surfaces and nanomaterial interactions.

Main Methods:

• Utilized a commercially available fluorescent probe targeting primary amines on bacterial cell surfaces.
• Applied the staining method to Gram-negative (Shewanella oneidensis MR-1) and Gram-positive (Bacillus subtilis 168) bacterial strains.
• Employed super-resolution microscopy techniques, including structured illumination microscopy (SIM) and stochastic optical reconstruction microscopy (STORM).

Main Results:

• Achieved efficient fluorescent staining of both Gram-negative and Gram-positive bacterial cell surfaces.
• Demonstrated sub-diffraction-limited resolution of bacterial cell surfaces using super-resolution microscopy.
• Successfully visualized the localization patterns of cadmium selenide quantum dots interacting with bacterial cells.

Conclusions:

• The developed fluorescent staining method is effective for bacterial cell surfaces across different Gram types.
• This technique is compatible with advanced super-resolution microscopy, offering enhanced visualization capabilities.
• The method facilitates the study of nanomaterial-bacteria interactions at the nanoscale.