Table 2.
Comparison of high-resolution imaging techniques in molecular and cell biology [171]
| Technique/feature | Atomic force microscopy | Super-resolution microscopy (STED, PALM, STORM) | Transmission electron microscopy | Scanning election microscopy |
|---|---|---|---|---|
| Resolution | ≤ 1 nm–50 nm | 20–50 nm | 0.2–10 nm | 2–10 nm |
| Sample preparation and environment | Sample on support; physiological (buffer solution, temperature, CO2) | Fluorescence labelling; physiological (buffer solution, temperature, CO2) | Sample on grid; dehydrated (negative stain); vitrified (cryo-electron microscopy) | Freeze/critical point drying and metal shadowing |
| Artefacts | Tip, force, scanning | Bleaching, toxicity | Dehydration, ice crystal formation, beam damage | Dehydration, metal shadowing, beam damage |
| Advantages | Imaging under native conditions; no staining, labelling, or fixation necessary; high signal-to-noise ratio; assessment of multiple physical, chemical, and biological parameters | Access to three-dimensional cellular structures; high spatiotemporal resolution; monitoring biomolecular processes in life cells | Solves atomic structures of proteins; conformational snapshot of proteins and complexes; molecular resolution of structures within the cell | Imaging surfaces of tissues, cells, and interfaces as nanometer-scale resolution |
| Limitation | Restricted to surfaces | Imaging restricted to fluorescence labels | No life processes | No life processes |
STED stimulated emission depletion, PALM photo activated localization microscopy, STORM stochastic optical reconstruction microscopy