Connective Tissues - Trichrome, Reticulin, Elastin (Wk 8) Flashcards
What colour does COLLAGEN stain in Van Gieson’s
Red
Removes red staining from collagen
Phosphomolybdic acid
What colour does MUSCLE stain in Masson’s Trichrome
Red
Main coloured staining component in Verhoeff’s
hematoxylin
Melanin staining is an ___________ reaction (type of silver rxn)
argentaffin
3 highly cellular tissues that reticulin would be found in
Liver
Lymph nodes
Spleen
In trichrome, aniline blue would most likely stain what?
Collagen
Type of hematoxylin required in the trichrome method
Iron
Typical stain for unsaturated lipids?
Oil Red O
Reticulin staining is an _________ reaction (type of silver rxn)
argyrophil
Stroma consists of ______ and connective tissue fibers
ECM
Why are only unsaturated lipids stainable w/ Oil Red O
Stain requires lipids to be liquid at room temp - only UNsaturated lipids can be liquid at RT (saturated lipids are solid)
Reagent used as a final differentiating wash in trichrome methods
Acetic acid
Chromophore in Oil Red O?
Diazo bonds
What 2 reagents do you combine to make ammoniacal silver?
Silver nitrate + ammonium hydroxide
This component has the larger pore size in the conventional theory of trichrome staining?
Collagen
This is the smaller dye used in Van Gieson’s.
Picric acid
This general type of hematoxylin is used when doing Van Gieson’s or Masson’s trichromes due to their acidic nature.
Iron mordanted
Final differentiating solution in many trichrome methods
acetic acid
Reticulin method - what reagent is used to detect the aldehydes created in the reticulin?
Ammoniacal silver
Stain that demonstrates elastin
Verhoeff’s
3 main components of Verhoeff’s
Hematoxylin
Ferric chloride
Iodine
This elastin stain is derived from lichens
Orcein
What colour does COLLAGEN stain in Masson’s trichrome?
Green or Blue
Why are the coloured molecules used in lipid stains technically not dyes?
No auxochromes
Cause of gray background in Verhoeff’s?
Due to iodine which is later removed with alcohol
Which component in Van Gieson’s is considered to be the cytoplasmic, muscle stain?
Picric acid
Routine stain that collagen stains with?
Eosin
Which component in Van Gieson’s will demonstrate collagen?
Acid Fuschin
What component of Gomori’s Reticulin stain removes unreduced silver and gold?
Sodium thiosulphate
4 components of Movat’s Pentachrome and what they demonstrate
Alcian blue - acid mucoproteins (light blue)
Hematoxylin - nuclei, elastin (dark blue)
Saffron - collagen (yellow)
Acid fuchsin - muscle, fibrin (red)
This chemical group is blocked by prolonged fixation in formalin and may result in poor trichrome staining.
Amino groups
Charge on all tissue components in trichrome method is ___________
cationic
Supportive structures of organs are called?
Stroma
Why is IRON hematoxylin required to stain nuclei in trichrome stains?
Due to strong acidity of staining solutions (can’t use reg hematoxylin)
What is used to differentiate in Verhoeff’s? What is the term for it?
Ferric chloride
Mordant differentiation
What colour does MUSCLE stain in Van Gieson’s
Yellow
Elastin is produced by __________ and ______________
fibroblasts, smooth muscle cells
2 functions of ferric chloride in Verhoeff’s
Oxidizing agent
Mordant
Oxidizes vicinal diols to produce aldehydes in the reticulin stain
Potassium permanganate (could also use periodic acid)
This is typically used as a secondary fixative when doing Masson’s Trichrome
Bouin’s
Stain that involves “mordant differentiation”
Verhoeff’s
Why is Bouin’s routinely used as a secondary fixative before trichrome staining?
Restores the lost positive charges from formalin fixation
Intermediate reagent used in some trichrome methods (mordant/colourless intermediate dye)
phosphomolybdic acid
Stain for saturated lipids?
Sudan Black
What component in the reticulin stain reduces ammoniacal silver to metallic silver?
Formalin
What is the charge of the dyes used in most trichrome methods?
Anionic
Ratio of picric/acid fuchsin in Van Gieson’s
50:1
3 types of connective tissue fibers
- Reticulin
- Elastin
- Collagen
Usual counterstain in Verhoeff’s?
Van Gieson’s
2 different words that refer to the coloured molecules in lipid stains
Lysochromes
Lipochromes
What is the general name for the stains used to differentiate between collagen and muscle.
Trichrome
This stain is a simpler and older trichrome method
Van Gieson’s
In the Gomori’s Reticulin silver method, what is used to detect aldehydes in the reticulin fibers?
ammoniacal silver
What is the process called in Gomori’s Reticulin method which uses gold chloride?
Toning
What stains collagen yellow in Movat’s pentachrome?
Saffron (not picric acid!)
2 most common special stains to demonstrate collagen
Masson’s trichrome stain
Van Gieson’s stain
2 examples of stroma?
Collagen, reticulin
Precaution when performing Verhoeff’s
Possible to over-differentiate
How to properly dispose of silver reagents?
Neutralize with salt (otherwise can form explosive compounds)
This reagent removes the connective tissue dye in Masson’s Trichrome.
Acetic Acid
Why must you avoid prolonged washing in water or dilute alcohol when doing Van Gieson’s?
Picric acid is water-soluble
What is the sensitizing reagent in reticulin stain?
Iron alum (follows oxidizing agent to enhance contrast)
What does it mean when the stain is an argentaffin reaction?
External reducing agent is NOT required to produce a visible product
This type of connective tissue fiber would be found in highly cellular tissues such as liver, lymph nodes, spleen
Reticulin
Main functional cells of an organ are called?
Parenchyma
e.g. hepatocytes
This term applies to items which are capable of reducing and binding silver, but require an external reducing agent in order to be visible.
Argyrophil
This is another name for Reticulin.
Type III Collagen
Purpose of potassium metabisulfite in reticulin stain?
Removes brown discolouration from potassium permanganate (oxidizing agent)
Why is using charged slides suggested for silver staining?
Ammoniacal silver is very alkaline which may cause the tissue to lift off the slide
