Chemical fixation works by denaturing and cross-linking proteins, which stabilizes the tissue's cellular architecture. This process involves several mechanisms:
- Cross-Linking: Fixatives like formaldehyde and glutaraldehyde form covalent bonds between amino acids in proteins, creating a stable network that immobilizes cellular components.
- Precipitation: Alcohol and other precipitants cause proteins and nucleic acids to coagulate, which helps in preserving the structural integrity.
- Oxidation: Fixatives such as osmium tetroxide oxidize double bonds in unsaturated lipids, providing excellent membrane preservation.
