Next time you see a stunning image from an electron microscope gracing the cover of a journal or textbook, check the photo credit—it could have been made right here at U of T’s microscopy imaging laboratory (MIL).
Researchers studying everything from fruit fly genetics to carbon nanotubes come to this crucial U of T facility to use advanced microscopic imaging technology to solve problems at the frontiers of medicine, engineering, botany and many other fields.
With two full-time staff and a budget of just $200,000, the lab provides a lot of bang for its buck. Its halls are lined with framed covers of scientific journals featuring images taken at the lab. Their images appear on the covers of journals like Nature Medicine and Advanced Materials about twice a year.
Tucked away in the basement of the Medical Sciences Building, the lab has gradually developed into a central facility as earlier microscopy labs dating back to the 1950s were amalgamated to save money. The MIL is directed by Dr. Umberto De Boni under the auspices of the faculty of medicine.
Researchers can use one of four electron microscopes at the lab to zero in on details just 50 billionths of a metre across. A laser optical microscope purchased this year can’t see details quite that small, but makes up for it with its ability to create 3-D pictures and to image living cells—something electron microscopes can’t do. Researchers can track the movements of specific proteins in cells using the laser microscope by treating the cells with special fluorescent dyes that only bind to specific proteins.
The MIL isn’t just about pretty pictures. 30 or so research teams use the microscopes on a regular basis because the images they take provide crucial insights that can’t be gained any other way.
Researchers in the auditory science laboratory in Sick Kids Hospital recently used images taken at the MIL to demonstrate scientists might be overlooking areas of the brain. These regions are important to certain tasks but don’t show up in positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) scans. Technologies like PET and fMRI track increases in blood flow in order to determine which parts of the brain are active during different tasks.
By comparing such brain scans with electron microscope images of the brain, researchers from the auditory science laboratory determined what actually shows up in brain scans is increased blood flow in certain dense clumps of blood vessels—clumps that are distributed very unevenly throughout the brain. If a group of neurons is involved in a given task but doesn’t require a large blood supply, it would be invisible to conventional brain scans. Their work made the cover of Cerebral Cortex in March, along with one of the images taken at the MIL.
Sometimes images from the lab can untangle longstanding riddles.
U of T microbiologist Ricky Chan was recently puzzling over a species of diarrhea-causing bacteria. When grown in a hostile environment, the bacteria, though still alive, become immobile—but the researchers didn’t know why. Yet mutated versions of the bacteria grown under the same conditions were able to move around just fine.
“As soon as we saw the images, we had the answer,” said Steven Doyle, the lab’s assistant manager.
The regular bacteria had become deformed in the hostile environment, but the mutants had developed normally despite the adverse conditions. Chan thinks the deformation prevented the bacteria from using their whip-like tails properly, which they use to swim.
The lab was also involved in the early stages of the development of fuel cell technology now used by Ballard Power Systems. A key problem at the time was getting a smooth distribution of the platinum particles that act as catalysts in the fuel cell. Researchers used the lab’s microscopes to study how different preparation techniques affected this distribution.
More than a mere equipment repository, the MIL has become a meeting place for researchers from separate fields to share their know-how with one another. Because so many researchers use the facility, techniques developed by one team often spread through word of mouth to other users, who then apply it to their own research.
“It’s a bit of a community,” said Battista Calvieri, the lab’s manager.
U of T has a distinguished history when it comes to the electron microscope. An early model built here in 1938 was the basis for the first commercial electron microscope made in North America, built by RCA.
