Fixation

Definition

Fixation is a technique used to preserve and stabilize biological tissues for microscopic examination. It involves treating specimens with chemicals or physical methods to prevent decomposition.

5 Must Know Facts For Your Next Test

1. Fixation can be achieved using chemical fixatives like formaldehyde or physical methods such as heat.
2. The primary purpose of fixation is to maintain the structure and composition of cells and tissues for observation.
3. Fixation helps in preventing autolysis and putrefaction, which can degrade cellular structures.
4. Common fixatives include aldehydes, alcohols, and oxidizing agents.
5. Proper fixation is crucial for subsequent staining procedures, enhancing the contrast and visibility of microscopic specimens.

Review Questions

• What are the two main types of fixation techniques?
• Why is fixation important before staining microscopic specimens?
• Name three common chemical fixatives used in microbiology.

Related terms

Staining:

The process of adding dyes to specimens to enhance contrast under a microscope.

Formaldehyde:

A common chemical fixative used to preserve biological tissues by cross-linking proteins.

Autolysis: The self-digestion or degradation of cells by their own enzymes.