Microscopy, what we can and wish to image
Miettinen, Riitta (2016)
2016
Biotekniikan koulutusohjelma
Luonnontieteiden tiedekunta - Faculty of Natural Sciences
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Hyväksymispäivämäärä
2016-06-08
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:tty-201602193541
https://urn.fi/URN:NBN:fi:tty-201602193541
Tiivistelmä
Microcopy has always been an important tool to increase our knowledge about structural elements that are responsible for the functional outcome of living organisms. Unraveling the relationship between the structure and function is of crucial importance for our understanding e.g. normal and pathophysiological events. “Structure without function is dead and a function without a structure is a ghost”, summarizes the importance of this relationship. In this thesis, the main principles of the microscopes used nowadays in life sciences are described followed by a discussion about the needs met by now and those that can be predicted to be also major issues in the future. The final aim is to find ideas to develop a new microscopic imaging system.
It is already 400 years since the first microscope was used. However, the major innovations and development in microscopy were done during the last 50-60 years. Highlights can be set on novel fluorescent probes and innovative methods utilizing signal processing and computation with which light microscopy has been pushed over the diffraction limit of light i.e. 200 nm. Super resolution microscopy provides detections of structures, complexes and individual proteins by fluorescent probes with a resolution around 10 nm. It is a powerful tool for both spatial and temporal imaging of living organisms. However, the major limitation is that laser beam techniques require structures to be labeled with fluorescence probes and, thus, visualizes the probe and not the structural element itself. Transmission electron microscopy, on the other hand provides super resolution (up to 0.14 nm) images about the structure and its components directly. Unfortunately, it is still practically impossible to image temporal events in living cells with electron microscope. Thus, we still have a big gap between light and electron microscopy. It is suggested in the current thesis that the microscopic systems that are based on second or third harmonic generation combined with lens free tomographic imaging and/or 4D ultrafast electron microscopy could be building blocks for a new type of microscope.
It is already 400 years since the first microscope was used. However, the major innovations and development in microscopy were done during the last 50-60 years. Highlights can be set on novel fluorescent probes and innovative methods utilizing signal processing and computation with which light microscopy has been pushed over the diffraction limit of light i.e. 200 nm. Super resolution microscopy provides detections of structures, complexes and individual proteins by fluorescent probes with a resolution around 10 nm. It is a powerful tool for both spatial and temporal imaging of living organisms. However, the major limitation is that laser beam techniques require structures to be labeled with fluorescence probes and, thus, visualizes the probe and not the structural element itself. Transmission electron microscopy, on the other hand provides super resolution (up to 0.14 nm) images about the structure and its components directly. Unfortunately, it is still practically impossible to image temporal events in living cells with electron microscope. Thus, we still have a big gap between light and electron microscopy. It is suggested in the current thesis that the microscopic systems that are based on second or third harmonic generation combined with lens free tomographic imaging and/or 4D ultrafast electron microscopy could be building blocks for a new type of microscope.