![]() Because the instruments use very small apertures and reject a great deal of light, they require high-intensity excitation sources, objectives with high numerical apertures and specimens that emit bright signals. Laser-based confocal systems are ideal for researchers who need a high degree of confocality. For instance, the Fluoview FV1000 SIM system offers two scan heads: One allows photoactivation or bleaching, and the other simultaneously collects the image. These instruments allow extremely thin optical sectioning of specimens, enabling structures and intracellular features deep within the specimen to be viewed, and the laser provides a very intense, small spot of light that can easily be used for purposes other than imaging, such as photobleaching and molecular uncaging. Laser scanning confocal microscopes offer advantages, particularly in imaging thick cells with a high density of intracellular components. The excitation laser source scans across the specimen in a point-by-point raster pattern to form a complete image of the focal plane, and often a series of sections taken through the specimen are reconstructed and displayed in three dimensions. In laser scanning confocal systems, point laser excitation and the emission pinhole combine to remove most out-of-focus light. ![]() Different confocal systems allow biologists to balance two sometimes incompatible priorities - rejecting as much unwanted light as possible while maintaining a detectable signal and perhaps a viable specimen. Various confocal methods can remove out-of-focus light to reveal the structures. When imaging thick biological specimens, light from out-of-focus planes often obscures the fluorescence of structures of interest. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |