Tissue preparation, fixation, and embedding

Summary

Authors

Brendan Choat, Steven Jansen

Definition

Tissue preparation by for storage, sectioning and microscopy. This involves the process fixation, which kills tissue and prevents decay, and embedding, which stabilizes tissue in wax or plastic to facilitate sectioning.

Methodological approaches

Prior to making anatomical observations using microscopy, plant tissue is generally fixed. Fixation is often the most important steps in microscopic observation of plant tissue. The main goal of fixation is to preserve the tissue or cells in a condition as close to the living state as possible. This requires that biochemical reactions are terminated quickly and in particular, that proteolytic enzymes are disabled. The fixative should also prevent damage to the sample by bacteria or other microorganisms.

There are an enormous variety of fixation procedures and protocols. The particular methods applied depend upon the tissue or cell ultrastructures being targeted for observation. Although the aim of fixation is to preserve the samples in their natural condition, it will inevitably lead to some structural artifacts. It is therefore very important to select the best method of fixation for a given set of observations in order to minimise structural and staining artifacts. It is also important to become familiar with unavoidable artifacts associated with a given type of fixation so that they may be taken into account when making observations.

Light microscopy

Electron microscopy

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