TABLE 1.

Comparison of the developed protocols.

Method	Structural information, which can be collected	Time	Laboriousness and costs
Conventional scanning electron microscopy (SEM) visualization	External morphology with nanometer resolution, many cells can be examined, including automatic mode	Fast preparation and examination	Easy and cheap
Scanning electron microscopy examination of carbon coated trimmed monolayer	Internal morphology (full cell cross-sections) with nanometer resolution, many cells can be examined, including automatic mode	Slow preparation and fast visualization	Sample preparation is expensive and time-consuming. Visualization is easy, fast and can be automatized
Focused ion beam scanning electron microscope (FIB-SEM) tomography	True three-dimensional data with nanometer resolution. External and internal morphological features simultaneously.	Slow preparation and very slow data collection	Very expensive and extremely time-consuming