Resolving biofilm topography by native scanning electron microscopy

Abstract

Scanning electron microscopy (SEM) is a powerful tool for structural analysis, but it requires biological samples to undergo lengthy, chemically-complex multi-step preparation procedures, arguably altering some features in the sample. Here we report an ultra-rapid and chemical-free technique for visualizing bacterial biofilms at their native state. Our technique minimizes the time interval from culture to imaging to approximately 20 min, while producing high-resolution images that enable the detection of a variety of topographic features such as bacterial chains, and resolving cells from matrix. We analyzed images obtained from Bacillus subtilis biofilms, demonstrate the usefulness of this technique for multiple types of image analysis, and discuss its potential to be improved and adapted to other types of biological samples.

Quantification and modeling of mechanical degradation in lithium-ion batteries based on nanoscale imaging

“…Broad-ion-beam (BIB) milling of the cross-sections leads to flat and polished surfaces 34 . Chromium is sputter-coated on top of the sample to prevent local charging effects 35 .…”

Nanobiotic formulations as promising advances for combating MRSA resistance: susceptibilities and post-antibiotic effects of clindamycin, doxycycline, and linezolid

“…SEM has been implemented on biolms as it is an effective tool to show the ne details of living systems. 77 Using the standard stages of xation, post-xation, dehydration, mounting, and sputter coating, all biolm samples were prepared. To maintain the morphology of the biological sample, it was rst xed with aldehyde.…”

In situ Electron Microscopy of Complex Biological and Nanoscale Systems: Challenges and Opportunities

“…Although this review specifically focuses on liquid cell EM, where the sample is encapsulated or "sandwiched" in a liquid medium, open specimen holders (Nishiyama et al, 2010) used in atmospheric or environmental EM can also benefit from the use of microfluidic platforms for in situ imaging. Several studies have employed atmospheric or environmental EM for correlative imaging of biological systems, including neuronal networks (Sato et al, 2019a), secretory glands (Yamazawa et al, 2016), and bacterial chains in a biofilm matrix (Raab and Bachelet, 2017). The open-cell EM configurations use either lowvapor-pressure liquid or differential pumping (Takeda et al, 2015), and the microfluidics can adopt an open-channel-like design to implement into the EM stages.…”