Confocal microscopy employs point scanning and a pinhole aperture to effectively suppress out-of-focus light, producing high-contrast optical section images that can be reconstructed into three-dimensional datasets. It is a powerful tool for imaging thick tissue slices and 3D cellular structures, allowing researchers to explore spatial relationships and cellular distributions.

However, traditional point-scanning systems rely on photomultiplier tubes for fluorescence detection, which limits acquisition speed and the ability to capture fast dynamic events. To address these limitations, spinning-disk confocal microscopy was developed. By employing multiple rapidly scanning laser beams and a rotating pinhole disk, spinning-disk systems achieve high-speed optical sectioning while detecting fluorescence with cameras such as sCMOS or EMCCD. This approach enables simultaneous acquisition of large fields of view with minimal phototoxicity, making it particularly suitable for live-cell imaging and rapid 3D experiments.