TECHNOLOGY CENTER NEWS

See deep inside living organisms with advanced microscope at ALMS

Precise imaging of multiple fluorescent markers available through CNSI at UCLA

by Wayne Lewis

High-resolution imaging using the SP8 DIVE reveals the functional organization of complex anatomical structures in intact tissues, such as blood vessels shown here in the colon, over a large volume with subcellular resolution. (Sample courtesy Tache lab/Imaging ALMS lab)

Researchers at UCLA and beyond can conduct 4D imaging of physiological processes within living organisms using a microscope available from the Advanced Light Microscopy and Spectroscopy Laboratory of the California NanoSystems Institute at UCLA.

The Leica SP8 Deep In Vivo Explorer multiphoton microscope is the only one of its kind available on campus as a shared resource. Supported in part by a grant from the National Institutes of Health, the confocal microscope makes for sharper images of thin sections within thick samples — an especially attractive feature for biological inquiry, from neurobiology to plant physiology.

Features include multiphoton excitation, multicolor non-descanned tunable detection and lifetime imaging. With biological specimens, users are able to customize settings to capture up to four sources of fluorescence at the same time, picking up virtually any transgenic marker of interest.

“The DIVE has had a phenomenal impact on our research abilities,” said Laurent Bentolila, director of ALMS. “For example, one can now routinely discriminate otherwise inseparable fluorescent signals with negligible crosstalk.”

The Leica SP8 Deep In Vivo Explorer multiphoton microscope is the only one of its kind available on campus as a shared resource. Supported in part by a grant from the National Institutes of Health, the confocal microscope makes for sharper images of thin sections within thick samples — an especially attractive feature for biological inquiry, from neurobiology to plant physiology.

The microscope, part of the collection at the Leica Center of Excellence at CNSI, is available to investigators working in academia at UCLA and elsewhere as well as to those in industry. The ALMS facility remains online through the pandemic, with user applications subject to campus guidance meant to limit COVID contagion.

ALMS staff has developed a workflow that takes advantage of the DIVE’s combination of features — such as two-photon excitation, ultrafast lasers and single-photon counting detectors — to quickly produce high-throughput 3D images for segmenting, modeling and mapping the anatomical features of mesoscale organs such as the colon, the heart and brain organoids.

Taken together, the microscope’s capabilities have introduced previously unavailable possibilities for UCLA scientists.

“Working with the DIVE has been a real breakthrough in my research,” said Alexa Sadier, a postdoctoral researcher in ecology and evolutionary biology at the UCLA College. “It allowed me to explore patterns of cell division in 3D during the development of various species of bats caught in the wild. This has never been done before in nonmodel organisms.”

The DIVE allows researchers to make use of a variety of imaging techniques:
  • fluorescence lifetime imaging microscopy (FLIM) with Phasor analysis
  • single- and multi-photon imaging
  • second- and third-harmonic imaging
  • reflection imaging
  • in vivo imaging
  • resonance scanner for high-speed calcium imaging
  • motorized refractive index matching objectives for water and clarity

Users praise the DIVE’s combination of flexibility and speed.

“We were able to try a number of different imaging modalities,” said Hongda Wang, a UCLA doctoral student in electrical engineering. “Most important, it enables rapid whole-slide imaging of tissue sections and provides simultaneously captured multichannel images, with fluorescence intensity and lifetime information displayed in real-time.”

Those wishing to inquire about using the SP8 DIVE should contact Bentolila at lbento@chem.ucla.edu.