Fixation Part 3

Has 95% ETOH, Picric acid, and GHAc

Gendre’s (Alcoholic Formalin)

Advantage: good for microincineration techniques; Fixes sputum

Gendre’s (Alcoholic Formalin)

For gastrointestinal (GI) tissues, prostate biopsies, and bone marrow (BM)

Hollande’s

Made up of 2 formaldehyde residues linked by 3 carbon chains; Container must be refrigerated

Glutaraldehyde

For enzyme histochemistry and electron microscopy

Glutaraldehyde

ADV: more pleasant and less irritation compared to formalin

DADV: less stable and more expensive than formalin

Glutaraldehyde

Glutaraldehyde:

○ Polymer of Formalin

○ Powder in form, used in 4%

○ Plastic embedding

Paraformaldehyde

○ For ultrathin and electron microscopy

Paraformaldehyde

○ Acrolein in glutaraldehyde or formalin

Karnovsky’s Paraformaldehyde / Glutaraldehyde

○ For Electron Histochemistry & Electron Immunocytochemistry

Karnovsky’s Paraformaldehyde / Glutaraldehyde

ADV: no smudging of nuclei and distortion of staining compared with formalin

DADV: reduced staining capacity [Remedy: increase staining time]

40% Aqueous Glyoxal

Metallic Fixatives

● Most common metallic fixative; 5-7%

MERCURIC CHLORIDE

● Routine fixative of choice for preservation of cell detail in tissue photography

● Trichrome staining is excellent.

MERCURIC CHLORIDE

ADV: penetrates and hardens tissue rapidly

DADV: Banned worldwide d/t extreme toxicity; marked cell shrinkage [Remedy: add acid]

MECURIC CHLORIDE

Mercuric Chloride may form Black precipitates of mercury except in Heidenhain’s Susa, what is the Remedy?

Remedy: Dezenkerization

■ 0.5% iodine + 70% ETOH → H2O → 5% Na thiosulfate → H2O

○ HgCl2 + Potassium dichromate + glacial acetic acid

Zenker’s Fluid

○ Good general fixative for adequate preservation of all kinds of tissues

Zenker’s Fluid

○ HgCl2 + potassium dichromate + strong formalin (40%)

Zenker-Formol (Helly’s Solution)

○ For pituitary gland, bone marrow, & blood-containing organs

Zenker-Formol (Helly’s Solution)

○ Brown pigments are removed with saturated alcoholic picric acid or NaOH

Zenker-Formol (Helly’s Solution)

HgCl2 + NaCl + TCA + glacial acetic acid + formalin

Heidenhain’s Susa solution

Skin tumor biopsy

Heidenhain’s Susa solution

ADV: minimum cell shrinkage and tissue hardening due to counter-balance effect of acids and mercury:

Acids : swelling

Mercury: shrinkage

Does not produce black pigments

DADV: Weigert’s staining of elastic fibers not possible

Heidenhain’s Susa solution

Recommended for hematopoietic and lymphoid tissues

B-5 Fixative

Fixation Time: 4-8hrs

B-5 Fixative

Bone marrow biopsies

B-5 Fixative

Recommended for making smears of loose cells on slides

Shaudins