Vävnadspreparation

Vävnadspreparation is the process of preparing biological tissue samples for microscopic examination. This is a crucial step in histology and pathology, allowing for detailed analysis of cellular structure and organization. The specific methods employed depend on the type of tissue and the intended examination.

A common initial step is fixation, which preserves the tissue's structure by preventing autolysis and putrefaction. Various fixatives, such as formalin, are used depending on the target molecules or structures. Following fixation, dehydration is typically performed, usually by immersing the tissue in increasing concentrations of alcohol to remove water. This is followed by clearing, where the alcohol is replaced with a solvent like xylene that is miscible with both alcohol and the embedding medium.

Next, embedding is performed, where the dehydrated and cleared tissue is infiltrated and surrounded by a solid medium, such as paraffin wax or resin. This provides support for sectioning. Once embedded, the tissue block is thinly sliced using a microtome. These thin sections, known as the actual sample, are then mounted onto glass slides.

Finally, staining is applied to enhance the visibility of cellular components. Hematoxylin and eosin (H&E) is a widely used stain, with hematoxylin staining nuclei blue and eosin staining cytoplasm and extracellular material pink. Other specialized stains may be used to highlight specific structures or molecules. The prepared slides are then ready for observation under a microscope.