A microscope with super-resolution allows researchers to follow life’s processes in living cells, down to the level of individual molecules.
Vesa Loitto and Karin Öllinger use microscopy to see small details in cells. Photo credit Kajsa Juslin
The Nobel Prize in Chemistry was awarded in 2014 for discoveries that made super-resolution optical microscopes possible. Researchers at the Microscopy Unit in the Faculty of Medicine and Health Sciences broke out into wild cheering when it was announced. At the time, just over 5 years ago, the desire to one day own such a microscope was planted in Vesa Loitto, director of the unit. Today it has become reality.
“We have acquired a STED microscope from SciLifeLab in Stockholm. These cost many millions of Swedish crowns new, but we only needed to pay for the cost of transport here, a tiny fraction of the purchase price. The light source, however, was broken. We were a bit worried for a while, until we managed to get a new one under the terms of an advantageous service agreement. A new multiphoton laser would have cost over a million crowns” says Vesa Loitto.Kjersti Tunströmer studies how blood clots form. Photo credit Kajsa Juslin
It had long been generally accepted that we would never be able to see the really tiny structures in our world, such as viruses and proteins, in a light microscope. The resolution limit was believed to be half of the wavelength of light, 0.2 micrometres. However, the super-resolution STED microscope allows scientists to see details with a resolution of 50 nanometres – smaller than one thousandth of the thickness of a human hair. Another huge advantage is that this technology allows them to image living cells. They can, for example, watch how individual blood platelets move and come together to form a blood clot, see what happens when a cell surrounds proteins and other biomolecules to absorb them, and follow how harmful proteins spread from one nerve cell to the next in Alzheimer’s disease.
During his tenure as director of the Microscopy Unit, Vesa Loitto has worked intensively with the microscopy of living cells. The unit has equipment that ensures that the cells are kept in conditions similar to those in the body. The temperature must be just right, and the atmosphere must have the right concentrations of carbon dioxide and oxygen.Anton Nordeman investigates what happens in the brain in dependency disorders. Photo credit Kajsa Juslin
“Successful microscopy on living cells also requires that we illuminate them as little as possible. You have to remember that cells from the interior of the body have never been exposed to light”, says Vesa Loitto.
Professor Karin Öllinger is head of a research group that is studying the function of the lysosome, a small structure found in cells. They are looking at the possible role of the lysosome in conditions such as cancer.
“The fact that we can see how it really moves in the cell – that’s what I find most fascinating about these techniques. Other methods give us tables of numbers, but here we can see events as they happen. You can’t beat that!”
The unit also has several electron microscopes. They have a resolution that is many times higher than that of light microscopes. However, the disadvantage of electron microscopes is that they cannot be used on living material. In other words, there’s no single microscope that is best for everything. The best technique is the one that helps the researchers answer their questions. Vesa Loitto acts as a sounding board and gives advice about what is most suitable in each case.Vesa Loitto, director of the Microscopy Unit. Photo credit Kajsa Juslin
“The best thing about working here is helping the scientists. Here I can get involved in the research, without having responsibility for it.”
The unit welcomes researchers from the university, Region Östergötland and external bodies. Karin Öllinger is a member of the steering group for the Core Facility at the Faculty of Medicine and Health Sciences, of which the Microscopy Unit is one part.
“Research groups can seldom have this type of advanced, expensive equipment themselves. We have extremely high-quality microscopes and skilled personnel to operate them, who can also teach and help the researchers”, says Karin Öllinger.
Translated by George Farrants