FIXATIVES Flashcards
for routine Histopathologic techniques
Formaldehyde
traditional most common fixative
Formol saline
best general tissue fixative
10% NBF
ideal for silver impregnation
Formol saline
ideal for silver reticulum
Formol sublimate
has HgCl2
Formol sublimate
for GI tissues, bone marrow, prostate biopsies
Hollande’s
for microincineration techniques, fixes sputum
Gendre’s
for electron histochemistry, electron immunocytochemistry
Karnovsky’s paraformaldehdye/glutaraldehyde
acrolein in glutaraldehyde
Karnovsky’s paraformaldehyde/glutaraldehyde
powder in form
Paraformaldehyde
for ultrathin and electron microscopy
Paraformaldehyde
for acid mucopolysaccharide & mucin
Lead
Most common metallic fixative
Mercuric chloride
good general fixative and good for trichrome staining
Zenker’s
for pituitary gland, BM, blood containing organs, preserve cytoplasmic granules
Helly’s/Zenker-formol
for bone marrow biopsies
B5
minimum cell shrinkage and tissue hardening due to counter-balance effect of acid and mercury
Heidenhain’s Susa
precipitates all proteins, and preserves carbohydrates
Chromic acid
for mitochondria, chromatin, mitotic figures, golgi bodies, RBC and colloid-containing tissues
Regaud’s
for early degenerative processes and necrosis, demonstration of rickettsia and other bacteria
Orth’s
preserves lipids, mitochondria at pH 4.5-5.2, cytoplasm, chromatin, and chromosome
3% potassium dichromate
for glycogen preservation
Picric acid
for embryo and pituitary biopsies
Bouin’s
important for nuclear fixatives
Glacial acetic acid
Most rapid tissue fixative
Carnoy’s
Fixing brain tissues and rabies diagnosis
Carnoy’s
for dry and wet smears, BM smears, bacterial smears
100% methanol
Touch prep smears to be wright-stained
95% isopropyl alcohol
for enzyme studies, does not fix but preserve glycogen
70-100% ethanol
for mucopolysaccharides and nuclear CHONs
Newcomer’s
Pale yellow powder in water
Osmium tetroxide
Most common osmic acid fixative
Flemming’s
for cytoplasmic structures
Flemming’s w/o glacial acetic acid
Weak decalcifying agent
Tricholoroacetic acid
used at cold temp, for water diffusable enzymes, brain tissues
Acetone
Thermal coagulation of proteins
Heat