Live cell imaging requires microscopes that minimize phototoxicity, maintain cell viability, and provide high-resolution imaging over time. Common choices include:
1. Inverted Fluorescence Microscopes:
Widefield Microscopes: Equipped with environmental controls (temperature, CO₂, humidity) and sensitive cameras (e.g., sCMOS). Often paired with phase-contrast or DIC (Differential Interference Contrast) for label-free imaging.
Spinning Disk Confocal: Reduces photobleaching with faster scanning compared to traditional laser scanning confocal. Ideal for dynamic processes.
2. Light Sheet Fluorescence Microscopy (LSFM):
Illuminates only the focal plane, drastically reducing light exposure and enabling long-term imaging (e.g., hours to days).
3. Two-Photon Microscopy:
Uses near-infrared light for deeper tissue penetration and reduced phototoxicity, suitable for thick samples like 3D cultures.
4. TIRF (Total Internal Reflection Fluorescence):
Visualizes events at the cell membrane (e.g., vesicle trafficking) by imaging a thin (~100 nm) optical section.
5. Super-Resolution Microscopes (e.g., STED, SIM):
Achieve higher resolution but require careful optimization to balance light exposure and cell health.
6. Live-Cell-Optimized Systems:
Incorporate environmental chambers, adaptive optics, and low-light detectors (e.g., EM-CCD cameras).
Key Features for Live Imaging:
- Environmental Control: Maintains temperature, CO₂, and humidity.
- Fast Acquisition: Minimizes motion blur for dynamic processes.
- Low Phototoxicity: Filters, LED light sources, or light sheet illumination reduce damage.
Choose based on resolution needs, imaging duration, and sample sensitivity.
