Confocal microscopy explained

A confocal microscope uses a pinhole to reject out-of-focus light, producing sharp optical sections that can be stacked into 3D reconstructions.

Advantages over widefield fluorescence

• Improved contrast and axial resolution.
• Optical sectioning without physically cutting the sample.
• Co-localisation and 3D volume imaging.

Practical notes

Point-scanning confocals are versatile but slower; spinning-disk systems are faster and gentler for live cells. Photobleaching and phototoxicity must be managed with laser power and dwell time.