CONFOCAL & SPINNING DISK MICROSCOPES

Laser scanning microscopes were the first to emerge. Extremely versatile and therefore indispensable tools, they are installed on every light microscopy platform within the TRI network. They capture only the fluorescent signal originating from the focal plane, eliminating stray fluorescence from the planes above and below. Point-by-point laser illumination allows for great acquisition flexibility, including the specific ability to zoom in on the image up to the optical resolution limit (a few tens of nanometres). However, this high-resolution capability makes them somewhat slow, a limitation that can be overcome by resonant confocal systems, more sensitive detectors or spinning disk systems. They are divided into two types: single-photon confocal microscopes and two-photon confocal microscopes. The latter can penetrate deeper into matter and achieve better resolution.

The spinning-disk function, for its part, combines the speed of widefield microscopy with the resolution of a confocal. This technique uses lasers to illuminate the samples and ultra-sensitive cameras to detect the fluorescent signal. Unlike laser scanning confocal, the spinning disk illuminates the entire observation area simultaneously, thereby reducing acquisition time (around 150ms routinely) and consequently phototoxicity.