The modern light microscope was established at the beginning of the twentieth century and was followed by an avalanche of discoveries and developments thereafter. On one hand the hardware components of the microscope made big strides towards perfection and on the other hand the sample preparation became much more elaborate by taking advantage of molecular biology principles.

The respective domains (physics, chemistry and biology) that enabled the development of microscopy hardware and sample preparation methods are intertwined and inspired each other throughout recent history of light microscopy. Our Bioimage Core Facility can also be understood as an intersection of these domains in the context of light-microscopy. 

• Key hardware components
  • Objectives - Advances in glass manufacturing and optics made complex assemblies of lenses capable of correcting spherical and chromatic aberrations.
  • Light sources - LASER and LED allow for homogeneous and precise sample illumination.
  • High-speed scanning galvo mirror.
  • Filters and dichroic mirrors - Modern thin-film manufacturing provides the tool to accurately control the light wavelength in the optical path.
  • Point detectors: photomultiplier tubes (PMTs) and avalanche photodiodes (APDs).
  • Digital cameras: EMCCD, sCMOS, and hybrid detectors enable photon counting (high sensitivity) at ever faster frame rates.
  • Precision step motors for fast, coordinated sample positioning.
  • Modern computers - Data transfer bandwidth and processing power are a necessity for digital cameras. Furthermore, they enable post-acquisition processing of the data (image restoration, 3D reconstruction, quantification).
• Sample preparation milestones

   

  • Microtomes - Studying serial thin sections of a given specimen.
  • Biomarkers - Colour and fluorescent dyes enable contrast enhancement.
  • Antibody staining - Colouring specific structures in tissue and organisms.
  • Fluorescent proteins - Render proteins visible by attaching a fluorescent sequence that is (re)produced by the organism itself.
  • Fluorescent biosensors - Making functional aspects (in contrast to mere structure) or molecules visible. 
  • Tissue clearing - Allows light microscopy to be applied to thicker (bigger) samples - An alternative to serial sectioning.
  • Spontaneously blinking and transiently binding fluorophores.

   

Microscopy Techniques

The above mentioned knowledge and technologie lead to the development and implementation of numerous microscopy techniques and different setups. In the table bellow you find a list of well established microcopy techniques. Not all of these techniques are available through the core facility or a particular laboratory at our University. However, the microscopy core facilities in Switzerland are well networked. If a particular instrument is not available on campus, our staff will direct you to the closest core facility that has the instrument in question available.