Gewebepräparationen

Gewebepräparationen encompasses the processes and techniques used to prepare biological tissues for microscopic examination or other forms of analysis. This preparation is crucial for visualizing cellular structures and understanding tissue morphology. The primary goal is to preserve the tissue's architecture and chemical composition while making it suitable for observation.

Common steps in Gewebepräparationen include fixation, which involves rapidly killing cells and preventing autolysis and putrefaction. Fixatives, such as formaldehyde or ethanol, cross-link proteins and maintain tissue structure. Following fixation, tissues often undergo dehydration, typically using a series of increasing alcohol concentrations, to remove water. This is followed by clearing, where the alcohol is replaced with a solvent like xylene, which is miscible with both alcohol and the embedding medium.

The next stage is embedding, where the dehydrated and cleared tissue is infiltrated with a supportive medium, usually paraffin wax or resin. This provides a solid matrix that allows for thin sectioning. Sectioning is performed using a microtome to cut extremely thin slices of the embedded tissue, often just a few micrometers thick. These sections are then mounted onto microscope slides.

Finally, staining is applied to impart color to different cellular components, enhancing contrast and visibility. Various stains, such as Hematoxylin and Eosin (H&E), are used to differentiate structures like nuclei and cytoplasm. Other specialized techniques and stains exist for specific analytes or cellular features, depending on the purpose of the examination, which can range from routine diagnostics to advanced research.