Chemical fixatives

Definition

Chemical fixatives are substances used to preserve biological tissues by stabilizing their cellular components and preventing degradation. They are essential for maintaining the structural integrity of specimens for microscopic examination.

5 Must Know Facts For Your Next Test

1. Chemical fixatives work by cross-linking proteins and nucleic acids, thereby preserving the specimen.
2. Formaldehyde, glutaraldehyde, and ethanol are common examples of chemical fixatives used in microbiology.
3. Fixation is a crucial step before staining procedures to ensure that cells retain their shape and structure during microscopic analysis.
4. Different fixatives have varying levels of penetration; for instance, formaldehyde penetrates tissues quickly but fixes them slowly.
5. The choice of fixative can affect the staining results; thus, it's important to match the fixative with the intended staining technique.

Related terms

Staining:

A technique where dyes are used to enhance contrast in microscopic specimens.

Microscopy:

The use of microscopes to view small-scale structures not visible to the naked eye.

Formaldehyde:

A commonly used chemical fixative known for its ability to cross-link proteins and preserve tissue morphology.