ALDEHYDE FIXATIVES

Formalin

Oxidation of methanol

10% formol-saline

CNS tissues and post-mortem

10% formol-saline

Silver impregnation staining

10% formol-saline

Shrink tissues during alcohol dehydration (rem: secondary fixation)

10% formol-saline

Microanatomic and cytologic preservation

10% NBF

Prevents formalin pigments ppt

10% NBF

Iron-containing and elastic fibers (not stain well after susa, zenker, or chromate fixation)

10% NBF

For frozen sections

Formol-corrosive

Routine post-mortem tissues

Formol-corrosive

Silver reticulum methods

Formol-corrosive

Fixes lipids and does not need washing

Formol-corrosive

Forms mercuric chloride deposits (black)

Formol-corrosive

Inhibits or slows down decalcification

Gendre’s

Microinceneration techniques (good for dust/pollutants in lungs)

Hollande’s

GI tissues, prostate biopsies, bone marrow

Glutaraldehyde

Enzyme histochemistry and electron microscopy (ultrastructural)

Glutaraldehyde

Less irritating compared to formalin

Glutaraldehyde

Less stable and more expensive than formalin

Paraformaldehyde

Polymer of formalin, Powder in form, Plastic embedding (3 ps)

Karnovsky

For electron microscopy and electron immunohistochemistry

Karnovsky

Acrolein in glutaraldehyde or formalin

40% aqueous glyoxal

No nuclei smudging and staining distortion

40% aqueous glyoxal

Reduces staining capacity (rem: increase the staining time)