Tissue fixation
Tissue fixation, usually just fixation, is an important part of tissue preparation for histologic examination. It is typically done with formalin.
Implications
Pathologist have a great lifestyle 'cause tissue takes long to fix; the penetration of tissue by formalin is 1 mm/hour.[1]
Ratio
The dictum is:[2]
- The volume of fixative should be 10x the volume of specimen.
Tissue fixation
A list of fixatives:[3]
| Fixative | Comment |
|---|---|
| Formalin, neutral buffered | standard fixative |
| Formalin, unbuffered | ??? |
| Glutaraldehyde | electron microscopy |
| Ethanol | cytopathology |
| Carnoy | ??? |
| Bouin | toxic ??? |
| B5 | used for lymphoma, superior morphology - but toxic, not good for IHC & DNA analysis[4] |
Tissue fixation
Formalin
- May be written (incorrectly) as "formulin".
- Formaldehyde + methanol.
Fixing marking dye
To fix marking dye:
- Formal-acetic alcohol (FAA):[5]
- Bouin's solution.
Formal-acetic-alcohol
General:
- Different recipes exist.
One recipe:[6]
- Ethanol.
- Acetic acid.
- Formaldehyde.
- Methanol.
See also
References
- ↑ Gross rounds. 14 August 2009.
- ↑ URL: http://www.cap.org/apps/docs/committees/cancer/cancer_protocols/2011/UvealMelanom_11protocol.pdf. Accessed on: 27 March 2012.
- ↑ Hunt, JL. (Feb 2008). "Molecular pathology in anatomic pathology practice: a review of basic principles.". Arch Pathol Lab Med 132 (2): 248-60. doi:10.1043/1543-2165(2008)132[248:MPIAPP]2.0.CO;2. PMID 18251585. http://www.archivesofpathology.org/doi/pdf/10.1043/1543-2165%282008%29132%5B248%3AMPIAPP%5D2.0.CO%3B2.
- ↑ Bonds, LA.; Barnes, P.; Foucar, K.; Sever, CE. (Aug 2005). "Acetic acid-zinc-formalin: a safe alternative to B-5 fixative.". Am J Clin Pathol 124 (2): 205-11. doi:10.1309/29DA-CY9K-BHNW-4BG6. PMID 16040290.
- ↑ URL: http://www.brunelmicroscopes.co.uk/acatalog/Solvents___Reagents.html. Accessed on: 5 January 2011.
- ↑ URL: https://fscimage.fishersci.com/msds/45357.htm. Accessed on: 5 January 2011.