UM School of Medicine Confocal Core facility offers super-resolution microscopy to enhance imaging of subcellular structures

The University of Maryland School of Medicine (UMSOM) Confocal Microscopy Core facility is now offering researchers access to a state-of-the-art STED microscope that provides super-resolution imaging capabilities. It is the latest addition of an Abberior Facility Line STED microscope. The new technology provides funded researchers across the University of Maryland, Baltimore (UMB) campus with enhanced visualization of fine cell structures and mechanisms on a nanoscale. Acquired in 2024, it is one of only six STED microscopes available in the entire state of Maryland.

STED microscopy, also known as Stimulated Emission Depletion microscopy, is a powerful advancement in confocal imaging that provides clear views of the molecular complexes within cells that would typically be blurred by the diffraction of light, as seen in traditional confocal microscopes. The technology is capable of resolution nearly ten times higher than the diffraction limit, allowing researchers to view the finest details including organelles, cytoskeletal elements and proteins.

“STED provides us with a different perspective and dimension all together,” said Thomas Blanpied, PhD, Director of the Confocal Microscopy Core and Vice Chair of the Department of Physiology, Pharmacology and Drug Development. “It gives us access to the subcellular mechanisms, demonstrating how diseases can disorganize cellular organelles or how drugs cause cellular changes. This investment is critical in our efforts to better understand the body and address today’s health challenges.”

The UMSOM STED system is specially equipped with additional features including a live cell incubator, enabling the monitoring of cell changes in real-time and fluorescence lifetime imaging which allows researchers to closely examine protein to protein interactions and changes in the molecular environment such as pH, temperature, viscosity or ionic concentration. With the ultimate goal of advancing basic and translational research projects, UMB scientists have already used the STED microscope as part of a research grant or pilot study to visualize a wide array of fixed and live samples including brain slices, synapses, muscles, cilia, mitochondria, and red blood cells thus increasing their understanding of health conditions and mechanisms. This includes new knowledge of how synaptic transmission in the brain is impacted in neurological disorders.

To acquire such images, STED makes use of two laser beams, instead of a single laser beam used in traditional confocal microscopes. The single excitation laser beam is a focused beam of light used to “excite” the molecules to emit light or make them glow. This technique alone delivers a diffraction-limited view. However, with the addition of a STED laser beam, a donut shaped beam is used to turn off the glow of molecules around the central hole. Restricting the glowing molecules to a significantly smaller area enables the STED super-resolution focus. Without this technique, confocal imaging equipment is usually capable of resolution down to 200 nanometers. The UMSOM STED system is capable of an impressive 40 nanometers lateral resolution or 80 nanometers isotropic 3D spatial resolution.  

Earlier this year, Seth Ament, PhD, Associate Professor in the Institute for Genome Sciences and in the Maryland Psychiatric Research Center of the Department of Psychiatry, utilized STED capabilities to map the structure of nerve cell connections in human brain tissue. He presented the research at UMSOM’s first-ever Shark Tank competition and received $10,000 to advance the project and compare patients with and without schizophrenia. 

“STED microscopy allowed us to view the sub-synaptic organization of the two proteins, PSD-95 and Bassoon, that determine the efficacy of synaptic transmission in the cerebellum,” said Dr. Ament. This level of visualization will be pivotal in our understanding of how the structure of synapses differs in those with schizophrenia. We look forward to sharing these findings for the advancement of new therapies.”

Allan Doctor, MD, Professor of Pediatrics, has also utilized STED capabilities to examine the localization of red blood cell proteins for his laboratory’s research on blood oxygen transport. He is working on $46 million research grant to develop and test a whole blood product, storable at room temperature, that can be used to transfuse wounded soldiers in the field within 30 minutes of injury. 

“Red blood cells are responsible for oxygen transport throughout the body, so it’s important to understand how any changes in their physiology could affect their deformability, stability, and interactions with the vasculature much like what we see in sickle cell disease,” said Dr. Doctor. “STED is allowing us to clearly view red blood cell proteins in various oxygen environments which could help identify new therapeutic targets for blood disorders and improve patient care.”

The STED microscope is currently housed on the 5^th floor of the Bressler Research Building and is available to all users on a fee-for-service at $60 per hour during weekdays and $30 per hour on nights and weekends. Software updates are ongoing and additional analysis capabilities may be added in the future.

Funding for the technology was provided by UMSOM, the Departments of Physiology and Neurobiology, University of Maryland – Medicine Institute for Neuroscience Discovery (UM-MIND), and University of Maryland Greenebaum Comprehensive Cancer Center (UMGCCC).

For more information on STED training or to sign up for a complimentary session, contact Shilpa Dilip Kumar, PhD, Assistant Professor of Pharmacology & Physiology, Confocal Microscopy Core at sdkumar@som.umaryland.edu