Gewebepräparaten

Gewebepräparaten, also known as tissue preparations, are samples of biological tissue that have been processed and preserved for microscopic examination. This process is crucial in histology, pathology, and various biological research fields to study the structure and function of cells and tissues. The preparation typically involves several steps designed to maintain the tissue's integrity and allow for detailed visualization.

The initial step is fixation, where the tissue is immersed in a fixative solution. Common fixatives like formalin or ethanol halt cellular decomposition and preserve the tissue's morphology. Following fixation, dehydration is performed, usually by passing the tissue through a series of increasing alcohol concentrations to remove water. This is often followed by clearing, where a solvent like xylene is used to make the tissue transparent.

Next, the tissue is embedded in a solid medium, such as paraffin wax or plastic resin. This embedding provides support, allowing for the sectioning of the tissue into very thin slices using a microtome. These thin sections, typically only a few micrometers thick, are then mounted onto glass slides.

Finally, the sections are stained with various dyes. Stains like Hematoxylin and Eosin (H&E) are commonly used, with Hematoxylin staining cell nuclei blue and Eosin staining cytoplasm and extracellular material pink. These stains highlight different cellular components, making them visible under a microscope and enabling diagnosticians and researchers to identify abnormalities or study normal tissue architecture. Special stains exist for identifying specific structures or substances within the tissue.