SPECIAL STAINS PART 9 Flashcards
CONGO RED STAIN
What does congo red stain stains
is used to stain
amyloid
Amyloid is a protein deposited in the liver, kidneys, spleen or other ti
what is an amyloid
is an abnormally folded, fibrillar protein that deposits in extracellular spaces in organs under certain pathological conditions
pathological effects of amyloid
As it accumulates, it progressively replaces the normal tissue elements, and eventually results in loss of
function of vital organs, and ultimately, death
What is the general principle of congo red stain
Amyloid is similar in structure to cellulose, therefore it behaves similarly in its chemical reactions. It is a linear molecule, which allows azo and amine groups of the
dye to form hydrogen bonds with similar hydroxyl radicals of the amyloid.
What is the appearance of H & E stained amyloid tissues
amyloid appears as an amorphous, glassy,
eosinophilic material. Since this can be confused with some other materials, CR staining is needed to identify it
what does the term “apple-green birefringence” refers to
refers to a specific optical property observed when amyloid deposits are stained with Congo red and viewed under polarized light
How is apple-green birefringence achieved
Under polarized light (best viewed in a darkened room), Congo red-stained amyloid displays a distinct “apple-green” birefringence.
What are the symptoms of amyloidosis
1.Fatigue
2. weight loss
3. Shortness of breath
4. Swelling in the legs or ankles
5. Numbness or tingling in the hands or feet
6. Diarrhea
What are the effects of amyloid build up
Can make the organs not work properly.
What orans are affected my amyloidosis
The heart
Kidneys
Liver
Spleen
Nervous system
Digestive tract.
Who uses the Congo red stain
Researchers studying amyloidosis will routinely use this staining technique to detect the
presence of amyloid in their tissues of interest.
