WOODS HOLE, Mass. — Two heads are better than one, as the saying goes, and sometimes two instruments, ingeniously recombined, can accomplish feats that neither could have done on its own.
Such is the case with a hybrid microscope, born at the Marine Biological Laboratory (MBL), that for the first time allows scientists to simultaneously image the full 3D orientation and position of an ensemble of molecules, such as labeled proteins inside cells. The research is published this week in Proceedings of the National Academy of Sciences.
The microscope combines polarized fluorescence technology, a valuable tool for measuring the orientation of molecules, with a dual-view light sheet microscope (diSPIM), which excels at imaging along the depth (axial) axis of a sample.
This scope can have powerful applications. For example, proteins change their 3D orientation, typically in response to their environment, which allows them to interact with other molecules to carry out their functions.
“Using this instrument, 3D protein orientation changes can be recorded,” said first author Talon Chandler of CZ Biohub San Francisco, a former University of Chicago graduate student who conducted this research partly at MBL. “There’s real biology that might be hidden to you from just a position change of a molecule alone,” Chandler said.
Imaging the molecules in the spindle of a dividing cell – a longstanding challenge at MBL and elsewhere — is another example.
“With traditional microscopy, including polarized light, you can study the spindle quite nicely if it’s in the plane perpendicular to the viewing direction. As soon as the plane is tilted, the readout becomes ambiguous,” said co-author Rudolf Oldenbourg, a senior scientist at MBL. This new instrument allows one to “correct” for tilt and still capture the 3D orientation and position of the spindle molecules (microtubules).
The team hopes to make their system faster so that they can observe how the position and orientation of structures in live samples change over time. They also hope development of future fluorescent probes will enable researchers to use their system to image a greater variety of biological structures.
