Table 1.
Comparison of high-resolution imaging techniques for applications in molecular and cell biology.
| Characteristics | Atomic force microscopy (AFM) | Super-resolution optical microscopy (STED, PALM, and STORM) | Scanning electron microscopy (SEM) | Transmission electron microscopy (TEM) |
|---|---|---|---|---|
| Spatial resolution | 1–50 nm | 20–50 nm | 2–10 nm | 0.2–10 nm |
| Specimen preparations | Living samples immobilized on support | Fluorescent labeling | Dehydrated and gilded samples on metal stubs | Dehydrated or vitrified samples on grids |
| Advantages | Topographical imaging and mechanical measurements under native conditions without pretreatments (e.g., fixation, lysis, labeling, or staining) | Observing three-dimensional cellular structures and molecular activities in life processes with high spatiotemporal resolution | Imaging surfaces of tissues, cells, and interfaces at nanometer resolution | Visualizing atomic structures of proteins and molecular-resolution structures within cells |
| Limitations | Restricted to the surface of samples and cannot access subsurface structures | Fluorescent labeling possibly affects the cellular and molecular behaviors | No life processes | No life processes |