Tissue fixation

From Libre Pathology
(Redirected from Fixation)
Jump to navigation Jump to search

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[4] electron microscopy
Ethanol cytopathology
Carnoy ???
Bouin toxic ???
B5 used for lymphoma, superior morphology - but toxic,
not good for IHC & DNA analysis[5]
IBF fixative used bone marrow and lymphatic tissue;[6] gives better nuclear detail in prostate biopsies compared to formalin[7]

Tissue fixation

Formalin

  • May be written (incorrectly) as "formulin".
  • Formaldehyde + methanol.

Fixing marking dye

To fix marking dye:

  • Formal-acetic alcohol (FAA):[8]
  • Bouin's solution.

Formal-acetic-alcohol

General:

  • Different recipes exist.

One recipe:[9]

  • Ethanol.
  • Acetic acid.
  • Formaldehyde.
  • Methanol.

See also

References

  1. Gross rounds. 14 August 2009.
  2. URL: http://www.cap.org/apps/docs/committees/cancer/cancer_protocols/2011/UvealMelanom_11protocol.pdf. Accessed on: 27 March 2012.
  3. 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.
  4. Prentø, P. (Nov 1995). "Glutaraldehyde for electron microscopy: a practical investigation of commercial glutaraldehydes and glutaraldehyde-storage conditions.". Histochem J 27 (11): 906-13. PMID 8787969.
  5. 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.
  6. URL: http://www.leicabiosystems.com/specimen-preparation/consumables/reagents-solutions/fixatives/details/product/ibf-tissue-fixative-1/. Accessed on: 26 September 2014.
  7. Trpkov, K.; Renault, P.; Yilmaz, A.; Ali-Ridha, N. (Jan 2006). "IBF as a formalin substitute fixative in prostate biopsy pathology.". Arch Pathol Lab Med 130 (1): 13-4. doi:10.1043/1543-2165(2006)130[13b:IAAFSF]2.0.CO;2. PMID 16390230.
  8. URL: http://www.brunelmicroscopes.co.uk/acatalog/Solvents___Reagents.html. Accessed on: 5 January 2011.
  9. URL: https://fscimage.fishersci.com/msds/45357.htm. Accessed on: 5 January 2011.

External links