In the laboratory, some photosensitive corals exhibit their own version of the observer effect: Exposing them to enough light for researchers to view them at microscopic scales changes the rates at which they grow and interact with symbiotic organisms such as algae. Scientists, however, want the coral polyps in their aquariums to act just as they would in the oceans.

Using the L-SPI microscope to visualize the re-infection of an Astrangia polyp (cyan from reflected light) with algae (red from chlorophyll fluorescence), injected by pipette into the mouth of the polyp. Credit: Loretta Roberson, MBL
Using the L-SPI microscope to visualize the re-infection of an Astrangia polyp (cyan from reflected light) with algae (red from chlorophyll fluorescence), injected by pipette into the mouth of the polyp. Credit: Loretta Roberson, MBL

To avoid disturbing their sensitive subjects, scientists in the United Kingdom and the United States have developed a light-sheet illumination system for performing fluorescence microscopy on coral polyps in captivity (Sci. Rep., doi: 10.1038/s41598-020-67144-w). Restricting the illumination to the focal plane of the microscope setup allows researchers to study the live creatures for extended time periods with minimal exposure to light. Read more of the article here.

Source: Imaging Photosensitive Corals | Optics & Photonics News