Light microscopy allows discovering the microcosmos that surrounds us with our own eyes using the visible light. By creating a spacial images of a given specimen, microscopy is a formidable tool to explore tiny structures and explore the spacial organisation of cells and tissues.
Related core facilities:
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 applying principles of molecular biology.
The respective domains (physics, engineering, molecular biology) that enabled the development of microscopy hardware and sample preparation methods are intertwined and inspired each other throughout recent history of light microscopy. However, the core facilities the microscopy hardware, while the sample preparation is elaborated by the research groups.
Key hardware components
- Objectives - Advances in glass manufacturing and optics made objectives complex assemblies of lenses capable of correcting spherical and chromatic abberrations.
- Light sources - LASER and LED allow for homogeneous and precise sample illumination.
- Filters and dichroic mirrors - Modern thin film manufacturing provides the tool to accurately control the light wavelength in the optical path.
- Photon detectors: EMCCD, sCMOS and hybrid detectors enable photon counting (high sensitivity) at ever faster frame rates.
- 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 - Color and fluorescent dyes enable contrast enhancing.
- 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.
- Tissue clearing - Allows to apply light microscopy to thicker (bigger) samples - An alternative to serial sectioning.
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.
axial - res.
|Bright-field1||Transmitted light||Thin, translucent||300nm,
|FRET2||Molecular interaction (proximity)||Fluorophore FRET-pair|| 1-10nm,
|FRAP3||Protein production and diffusion||Fluorescent protein||-|
|FLIM/TCSPC9||Fluorescent life-time measurement||Any fluorescence||-|
|Holotomography||Label-free, 3D||Thin, translucent||200nm,
|TIRF4||Evanescent excitation light||Fluorophore near coverslip||230nm,
|Laser scanning confocal||High contrast, up to ~300um deep.||Fluorescent labels||200nm,
|Spinning disk confocal||Fast, high contrast, up to ~150um deep.||Fluorecent labels||200nm,
|Multi-photon||Confocal for deep tissue imaging||Special fluorophores||300nm,
|SIM||Fast super resolution||Fluorecent labels||100nm,
|STED||3D super resolution||Special fluorophores||50nm,
|Light sheet||Fast, photon-economic 3D imaging.||Sample holder compatible||
|Single molecule detection||
|Photoactivatable or blinking fluorophores||10–100nm,
1: Incl. dark-field, phase contrast, differential interference contrast (DIC) , polarised light
2: Förster resonance energy transfer
3: Fluorescence recovery after photobleaching
: Available through core facilities
: Existing setup in laboratories
: Not available at the University of Fribourg