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Wymke Ockenga

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Wymke Ockenga studied Human Biology at the Philipps-Universität in Marburg. Her main subjects were cell biology and biological chemistry. She did her diploma thesis at the Institute for Cytobiology and Cytopathologie and is currently working as a PhD student at the Justus-Liebig-Universität in Gießen.

  • A Brief History of Light Microscopy – From the Medieval Reading Stone to Super-Resolution

    The history of microscopy begins in the Middle Ages. As far back as the 11th century, plano-convex lenses made of polished beryl were used in the Arab world as reading stones to magnify manuscripts. However, the further development of these lenses into the first microscopes cannot be attributed to any one person. It took the ideas and designs of many scientists and scholars to produce instruments capable of strong magnification.
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  • How to Clean Microscope Optics

    Clean microscope optics are essential for obtaining good microscope images. If they are dirty, the microscope should be cleaned to avoid a loss of quality. If you decide to do this yourself, you should be extremely careful not to damage the sensitive microscope optics.
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  • Total Internal Reflection Fluorescence (TIRF) Microscopy

    Total internal reflection fluorescence (TIRF) is a special technique in fluorescence microscopy developed by Daniel Axelrod at the University of Michigan, Ann Arbor in the early 1980s. TIRF microscopy delivers images with an outstandingly high axial resolution below 100 nm. This allows the observation of membrane-associated processes.
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  • Applications of TIRF Microscopy in Life Science Research

    The special feature of TIRF microscopy is the employment of an evanescent field for fluorophore excitation. Unlike standard widefield fluorescence illumination procedures with arc lamps, LEDs or lasers, the evanescent field only penetrates the specimen by about 100 nm starting from the coverslip/medium interface.
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  • Optical Contrast Methods

    Optical contrast methods give the potential to easily examine living and colorless specimens. Different microscopic techniques aim to change phase shifts caused by the interaction of light with the specimen into amplitude shifts that are visible to the human eye as differences in brightness.
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  • Phase Contrast

    Phase contrast is an optical contrast technique for making unstained phase objects (e.g. flat cells) visible under the light microscope. Cells that appear inconspicuous and transparent in brightfield can be viewed in high contrast and rich detail using phase contrast microscopy.
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  • Differential Interference Contrast (DIC)

    Differential interference contrast (DIC) microscopy is a good alternative to brightfield microscopy for gaining proper images of unstained specimens that often only provide a weak image in brightfield.
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  • An Introduction to Fluorescence

    Fluorescence is widely used in microscopy and an important tool for observing the distribution of specific molecules. Most molecules in cells do not fluoresce. They therefore have to be marked with fluorescing molecules called fluorochromes.
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  • Photo Effects of Light

    Molecules and atoms can exist in different quantum states. These states are dedicated to different energy levels; the quantum state with the lowest energy is called the ground state. Every state of greater energy is an excited state of the quantum mechanical system. Electrons can be excited by an exogenous energy source and switch to a higher energy level, changing the quantum state of the molecule or atom. The electrons are often referred to as being brought to a state of higher energy.
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  • Polarization Contrast

    Polarization microscopy is routinely applied in material sciences and geology to identify minerals on the basis of characteristic refraction properties and colors. In biology, polarization microscopy is commonly used for identification or imaging of birefringent structures like crystals, or for imaging of cellulose in cell walls of plants and starch grains.
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  • Fluorescence in Microscopy

    Fluorescence microscopy is a special form of light microscopy. It uses the ability of fluorochromes to emit light after being excited with light of a certain wavelength. Proteins of interest can be marked with such fluorochromes via antibody staining or tagging with fluorescent proteins.
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